JP2023152304A - Mobile terminal handover using lower address memory that stores lower addresses of mac addresses for add, drop, and transfer device in ring network - Google Patents

Abstract

To realize handover of a wireless system at low cost and at high speed.SOLUTION: In a case in which a packet from a TCP mobile terminal 13 via a base station 12 arrives at an add, drop, and transfer device 6 of a ring network or a tree-like ring network, when a base station gives a signal indicating that the packet has just moved from the base station, a lower address of a packet source MAC address of a packet is stored in a lower address memory 7 that specifies sending of the packet outside the ring of the add, drop, and transfer device, the source MAC address is deleted from an address table 8 that specifies the transfer of the packet, and when the packet is directed to a server 20 via an apex device 5 in a counterclockwise ring 1, and the packet arrives at the add, drop, and transfer device, the lower address of the source MAC address of the packet is deleted from the lower address memory, and the packet is directed to the server via the apex device in the counterclockwise ring.SELECTED DRAWING: Figure 1

Description

The present invention relates to handover of a mobile terminal using a lower address memory that stores lower addresses of MAC addresses as a device for adding, dropping, and passing packets in a ring network. In the present invention, a packet transferred using only the MAC address portion of the IPv6 address of an Ethernet frame (registered trademark) or an IPv6 packet is referred to as a MAC packet.

A conventional example of an address storage method is JP-A No. 2000-151617 "Table Creation and Search Device" in Patent Document 1. This conventional example relates to a MAC address storage circuit, and includes a first table composed of a RAM having a matrix address, a MAC address data area, and an index area, and a RAM having a matrix address, a MAC address data area, and an index area. The second table consists of the following table. In this conventional example, the entire 48 bits of the MAC address are stored at location A, which specifies the memory of the first table using the lower bit string (for example, 16 bits). If another MAC address is already stored in that location A, it is recorded in a free address location B in the memory of the second table, and the recorded address location B is stored in the address location A of the first table. Store in the index area. This is a method of specifying recording areas by nesting.

Further, as a conventional technique of an address storage method, there is Patent Document 2, JP-A No. 2004-15592 entitled "MAC address pointer structure and MAC address sorting method". This conventional example is a method of storing a plurality of MAC addresses at the same address position in an entry table specified by a lower bit string. If there is no free area, the MAC address is stored in an entry table specified by a lower bit string different from the lower bit string of the MAC address.

As a conventional example of a ring type network, a ring network using a master switch and a slave switch as in Patent Document 3 is common. In this ring network, one ring port of the master switch is a blocked port that does not allow frames to pass, to prevent congestion due to flooding. When a failure occurs in the ring network, the monitoring frames that go out from the master switch and return to the master switch no longer reach the master switch, and instead failure notification frames arrive at the master switch from the slave switch at the point of failure. unblocks the blocked port and allows the frame to pass. In addition, a block port is set on the failed transmission line side of one of the slave switches at the failure point, and the operation of the ring network is maintained even after the ring network failure is recovered.

Further, as a conventional example of handover in a wireless network, there is Patent Document 4. This prior art involves handover of a network in which a control station that transfers ATM cells communicates with a mobile terminal via a base station based on the delay D1 from the control station to the mobile terminal via the source base station and the delay D1 at the destination. In the case of a difference in delay D2 from the base station to the mobile terminal (D1-D2>0), when switching the base station of the ATM cell sent from the control station to the mobile terminal, the ATM cell is delayed at the control station, This method is implemented by switching to prevent the order of ATM cells from being reversed.

Further, as an example of another handover method, there is Patent Document 5. This prior art has a base station between the mobile terminal and the server, a connection via the base station before switching via the gateway, and a connection via the switching destination base station, and packets via the connection reduce downtime when the connection is switched. It's a method.

Japanese Patent Application Publication No. 2000-151617 Japanese Patent Application Publication No. 2004-15592 Re-table No. 2008-068813 Japanese Patent Application Publication No. 2001-128212 Re-table No. 2017-195497

A conventional example of a conventional address storage method, JP-A No. 2000-151617, stores MAC addresses by nesting, so there is a problem in that it takes time to trace the destination of a stored address. Furthermore, since the entire 48 bits of the essential MAC address are stored, there is a problem that the storage area becomes large.

Furthermore, a conventional example of a conventional address storage method, JP-A No. 2004-15592, states that if there is no free space in the entry table position of the MAC address specified by the lower bit string, the MAC address is stored in the entry table position of a different lower bit string. However, in that case, when selecting the location to store the MAC address, the entry table location specified by the two lower bit strings must be searched, and the same address location in the same entry table must be searched. Since there are multiple storage addresses, it is necessary to compare these multiple addresses, and there is a problem in that the search takes time.
Searching for a MAC address using the lower bit string becomes faster, but basically the method of storing the entire MAC address in the lower bit string position is accurate storage, but since the entire 48 bits must be stored, the number of stored addresses decreases. There are fewer problems.
Patent Document 3, which is a conventional ring network, uses a MAC address table using 48 bits of MAC addresses, so it has the disadvantage that it can only store a small number of MAC addresses.

In the conventional handover patent document 4, it is necessary to find the difference in delay between the pre-switching route and the post-switching route from the control station to the mobile terminal, and the control is complicated. Since it can only be measured as half of the time it takes to travel back and forth from the terminal to the mobile terminal, there is a problem that the accuracy of the delay time measurement is lacking.

Further, in the conventional handover disclosed in Patent Document 5, two connections are provided between the server and the mobile terminal for switching, so it is necessary to identify the two connections, which has the disadvantage of complicating handover control.

An object of the present invention is to use a conventional address storage method that does not use a MAC address table in a lower address memory that stores lower addresses of MAC addresses, and to facilitate simple handovers and mobile terminals using a ring network using the memory. The purpose of this study is to show a method for realizing short-distance movement of people.

The present invention has been made in view of the problems of the prior art described above, and the first aspect of the present invention is:
A wireless base station is accommodated in a ring network or the lowest ring of a tree-like ring network, and a mobile terminal under the wireless base station receives MAC packets other than OAM packets arriving from the clockwise ring of the ring network or tree-like ring network. A packet transfer system that enables movement between the wireless base stations of a mobile terminal in a network that communicates TCP or UDP MAC packets with a server connected via a router to an apex device that blocks passage of packets,
When a MAC packet from the mobile terminal via a base station arrives at a packet adding, dropping, and passing device of the ring network or tree-shaped ring network,
If the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets to which the destination base station is connected is a device in the direction away from the server on the counterclockwise ring,
The device for adding, dropping, and passing packets stores the lower address of the source MAC address of the packet in the lower address memory that specifies the sending of the packet outside the ring, and sends the packet from the address table that specifies the passing of the packet. If the original MAC address is deleted and the packet is sent to the server via the apex device in a counterclockwise ring, and the packet arrives at the device that adds, drops, and passes the packet, the packet is sent out of the ring. deleting the lower address of the source MAC address of the packet from a lower address memory specifying the packet, and directing the packet to the server via the apex device in a counterclockwise ring;
On the other hand, if the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets connected to the destination base station is the device approaching the server on the counterclockwise ring. ,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring of the device for adding, dropping, and passing the packet, and the lower address of the source MAC address of the packet is stored as the lower address of the packet. A lower address specifying the pass is stored in memory to direct said packet through the apex device in a counterclockwise ring to the server, and when the packet arrives at the packet add, drop, and pass device, it is If the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission, the source MAC address of the packet is stored in the address table that specifies the passage of the packet, and the packet to the server via the apex device in a counterclockwise ring;
Furthermore, if the packet is not a packet immediately after moving to the destination base station,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies the sending of the packet outside the ring of the device for adding, dropping, and passing the packet, and the packet is sent to the server via the apex device in the counterclockwise ring. When the packet arrives at a device for adding, dropping, and passing packets, the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission outside the ring. In this case, the source MAC address of the packet is stored in an address table that specifies passage of the packet, and if the source MAC address is stored as a new MAC address, and the source MAC address of the packet is if a lower address of is stored in a lower address memory specifying passage of the packet, means for erasing the lower address and directing the packet to the server via the apex device in a counterclockwise ring;
Packets other than the communication start packet, such as an incoming voice call packet, an SMS (Short Message Service) packet, or the first incoming FTP packet from the server, arrive at a device for adding, dropping, and passing packets in a clockwise ring. if you did this,
If the destination MAC address of the packet is stored in an address table that specifies passage of the packet, the packet is sent toward a device for adding, dropping, and passing the packet in front of the clockwise ring. , the destination MAC address of the packet is not stored in an address table that specifies the passage of the packet, and the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies the passage of the packet. and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, copy the packet and send the copied packet outside the ring. , sending the original packet towards a forward packet add, drop and pass device of the clockwise ring;
In cases other than the above, and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, the packet is sent outside the ring, and In this case, the packet transfer system is characterized by comprising means for transmitting the packet toward a device for adding, dropping, and passing packets forward of the clockwise ring.

A second aspect of the present invention specifies packet sending out of the ring of a device for adding, dropping and passing packets in a ring network or a tree-like ring network of the packet transfer system according to the first aspect of the present invention. In the lower address memory, if the lower address of the source MAC address of the packet is divided into an upper part and a lower part, and the bit string of either of them contains all bits 0, it is handled in a separate address table, and other parts are The address of the SRAM cell is the logical sum of each bit of the latch output of the parallel data read from the position specified by addressing the SRAM cell in the upper part and each bit of the parallel data decoded in the lower part. A memory that inserts and stores the lower part of the lower address of the source MAC address by storing it in a specified position, with bit 1 at the bit 1 position of decoding as bit 1 meaning lower address storage,
When deleting the lower address of the source MAC address from the lower address memory that specifies sending packets outside the ring, delete the lower address memory that specifies sending packets outside the ring with the upper part of the lower address of the source MAC address. A latch signal of the parallel data is output from the ring by ANDing each bit of the parallel data read from the addressed position and the bit inversion bit of each bit of the parallel data decoded from the lower part of the lower address of the source MAC address. By storing the lower part of the lower address of the source MAC address in the address specified position of the lower address memory that specifies packet transmission, insert bit 0 into the bit 1 position of decoding as bit 0, which means that the lower address is not stored. A lower address memory for specifying packet adding, dropping, and passing of a packet outside the ring of a ring network or a tree-like ring network of a packet transfer system, characterized in that it stores packets outside the ring.

A third aspect of the present invention is that a wireless base station is accommodated in a ring network or in the lowest ring of a tree-like ring network, and a mobile terminal under the wireless base station is connected to the ring network or the tree-like ring network in a clockwise direction. Blocking passage of MAC packets other than OAM packets arriving from the ring Enables mobile terminals in a network to communicate between the wireless base stations communicating TCP or UDP MAC packets with a server connected via a router to an apex device A packet transfer method, comprising:
When a MAC packet from the mobile terminal via a base station arrives at a packet adding, dropping, and passing device of the ring network or tree-shaped ring network,
If the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets to which the destination base station is connected is a device in the direction away from the server on the counterclockwise ring,
The device for adding, dropping, and passing packets stores the lower address of the source MAC address of the packet in the lower address memory that specifies the sending of the packet outside the ring, and sends the packet from the address table that specifies the passing of the packet. If the original MAC address is deleted and the packet is sent to the server via the apex device in a counterclockwise ring, and the packet arrives at the device that adds, drops, and passes the packet, the packet is sent out of the ring. deleting the lower address of the source MAC address of the packet from a lower address memory specifying the packet, and directing the packet to the server via the apex device in a counterclockwise ring;
On the other hand, if the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets connected to the destination base station is the device approaching the server on the counterclockwise ring. ,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring of the device for adding, dropping, and passing the packet, and the lower address of the source MAC address of the packet is stored as the lower address of the packet. A lower address specifying the pass is stored in memory to direct said packet through the apex device in a counterclockwise ring to the server, and when the packet arrives at the packet add, drop, and pass device, it is If the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission, the source MAC address of the packet is stored in the address table that specifies the passage of the packet, and the packet to the server via the apex device in a counterclockwise ring;
Furthermore, if the packet is not a packet immediately after moving to the destination base station,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies the sending of the packet outside the ring of the device for adding, dropping, and passing the packet, and the packet is sent to the server via the apex device in the counterclockwise ring. When the packet arrives at a device for adding, dropping, and passing packets, the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission outside the ring. In this case, the source MAC address of the packet is stored in an address table that specifies passage of the packet, and if the source MAC address is stored as a new MAC address, and the source MAC address of the packet is if a lower address of is stored in a lower address memory specifying the passage of the packet, clearing the lower address and directing the packet through the apex device in a counterclockwise ring to the server;
Packets other than the communication start packet, such as an incoming voice call packet, an SMS (Short Message Service) packet, or the first incoming FTP packet from the server, arrive at a device for adding, dropping, and passing packets in a clockwise ring. if you did this,
If the destination MAC address of the packet is stored in an address table that specifies passage of the packet, the packet is sent toward a device for adding, dropping, and passing the packet in front of the clockwise ring. , the destination MAC address of the packet is not stored in an address table that specifies the passage of the packet, and the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies the passage of the packet. and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, copy the packet and send the copied packet outside the ring. , sending the original packet towards a forward packet add, drop and pass device of the clockwise ring;
In cases other than the above, and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, the packet is sent outside the ring, and In this case, the packet transfer method includes the step of transmitting the packet toward a device for adding, dropping, and passing packets forward of the clockwise ring.

As described above, the present invention provides a lower address memory that stores only the lower address part of a MAC address in place of the conventional MAC address table, and a mis-allocation caused by mismatching of MAC addresses that occurs when using the lower address memory. This method uses an address table with a small number of stored MAC addresses in the device (node device) for adding, dropping, and passing packets in the ring network to avoid problems.This method reduces power consumption and the system. This has the effect of reducing costs and enabling high-speed communication.

The first embodiment of the present invention has an address table that specifies the passage of a packet, a lower address memory that specifies the sending of the packet to the outside of the ring, and a lower address memory that specifies the passage of the packet. A mobile terminal connected to the ring network via a router and a mobile terminal that transfers MAC packets through a wireless base station connected to a device for adding, dropping, and passing the packets in a dual ring network in which a plurality of devices are connected by an optical ring. Diagram for explaining an example of handover operation in a packet transfer system between servers The first embodiment of the present invention has an address table that specifies the passage of a packet, a lower address memory that specifies the sending of the packet to the outside of the ring, and a lower address memory that specifies the passage of the packet. FIG. 3 is a diagram illustrating a configuration example of a lower address memory that specifies packet transmission to the outside of the ring of the device.

A first embodiment of the present invention will be described with reference to FIG. This embodiment includes a plurality of devices for adding, dropping, and passing packets, each having an address table that specifies packet passage, a lower address memory that specifies packet transmission outside the ring, and a lower address memory that specifies packet passage. Between a mobile terminal that transfers MAC packets through a wireless base station connected to a device for adding, dropping and passing said packets in a dual ring network connected by an optical ring and a server connected to said ring network via a router. This is an example of handover operation of a mobile terminal using a ring network in a packet transfer system. The server is an Internet connection server or a content server.

In FIG. 1, 1 is a counterclockwise optical ring of the subscriber system, 2 is a clockwise optical ring of the subscriber system, 5 is a vertex device, and 6-1, 6-2, and 6-3 are packet add, drop, and pass packets. 7 is a lower address memory that specifies packet transmission to the outside of the ring, 8 is an address table that specifies packet passage, 10 is a lower address memory that specifies packet passage, 22 is a router, 12-1, 12 -2 and 12-3 are base stations; 13-1, 13-2, and 13-3 are TCP mobile terminals; 14 is a mobile terminal; and 20 is a server. Further, (1) to (34) are packets, and I0, I1, I2, I3, and I4 are domestic or regional IP addresses of the service provider. Or an IPv6 address.
Note that the address table 8 that specifies the passage of packets is different from conventional MAC address tables in that it is an address table that does not store port numbers and stores only a small number of MAC addresses.

The operation of FIG. 1 will be explained below. First, it is assumed that the TCP mobile terminals 13-1, 13-2, and 13-3 have already stored the IP address I1 of the router 22 and the MAC address r1r2 of the ring transmission path interface in their ARP tables. The TCP mobile terminal 13-2 sends a packet (1) Mr1r2a3a2 (I0) (M indicates an Ethernet packet, r1 indicates the upper MAC address of the router 22 interface, r2 indicates the lower MAC address of the router 22 interface, and a3a2 The MAC addresses of the TCP mobile terminal 13-2 (indicating the upper MAC address a3 and lower MAC address a2, and I0 indicating the IP address of the destination server 20) are sent to the packet adding, dropping, and passing device 6-1. An example of sending is shown below. When the packet reaches the add, drop, and pass device 6-1 from the TCP mobile terminal 13-2, the lower address a2 of the source MAC address of the packet is used as the lower address that specifies packet transmission outside the ring. It is stored in the address memory 7. The packet is transferred in the counterclockwise optical ring 1 by (2) Mr1r2a3a2 (I0) as shown in the figure, and arrives at the packet add, drop, and pass device 6-2.

When the packet (2) Mr1r2a3a2 (I0) arrives at the packet add, drop, and pass device 6-2, the lower address a2 of the source MAC address of the packet is a lower address that specifies packet transmission outside the ring. Since it is not stored in the memory 7, the packet is transferred in the counterclockwise optical ring 1 by (3) Mr1r2a3a2 (I0) as shown in the figure, and arrives at the packet add, drop and pass device 6-3.
When the packet (3) Mr1r2a3a2 (I0) arrives at the packet add, drop, and pass device 6-3, the lower address a2 of the source MAC address of the packet is the lower address that specifies the packet transmission outside the ring. Since it is not stored in the memory 7, the packet is transferred in the counterclockwise optical ring 1 by (4) Mr1r2a3a2 (I0) as shown in the figure, and reaches the vertex device 5. The packet is sent out of the ring and reaches router 22.

When the packet (5) Mr1r2a3a2 (I0) arrives at the router 22, the source MAC address a3a2 and source IP address I2 of the packet are stored in the memory 1 (not shown). The output port corresponding to the destination IP address I0 of the packet is found, and the packet is sent to that port. The packet is shown in the diagram by (6) IPI3I0 (IP indicates an IP address, I3 indicates the IP address of the source mobile terminal 13-2, and I0 indicates the IP address of the destination server 20). The data is transferred as follows and reaches the server 20.

Next, the TCP mobile terminal 13-1 sends packet (7) Mr1r2a1a2 (I0) (M indicates an Ethernet packet, r1 indicates the upper MAC address of the router 22 interface, and r2 indicates the lower MAC address of the router 22 interface. , a1a2 indicates the upper MAC address a1 and lower MAC address a2, which are the MAC addresses of the terminal 13-1, and I0 indicates the IP address of the destination server 20). Send to. When the packet reaches the add, drop, and pass device 6-1 from the TCP mobile terminal 13-1, the lower address a2 of the source MAC address of the packet is used as the lower address that specifies packet transmission outside the ring. It is stored in the address memory 7. The packet is transferred in the counterclockwise optical ring 1 by (8) Mr1r2a1a2 (I0) as shown in the figure, and arrives at the packet add, drop, and pass device 6-2.

When the packet (8) Mr1r2a1a2 (I0) arrives at the packet add, drop, and pass device 6-2, the lower address a2 of the source MAC address of the packet is the lower address that specifies the packet transmission outside the ring. Since it is not stored in the memory 7, the packet is transferred by (9) Mr1r2a1a2 (I0) in the counterclockwise optical ring 1 as shown in the figure, and passes through the packet add, drop and pass device 6-3, The vertex device 5 is reached.

The packet that has arrived at the apex device 5 is sent out of the ring and reaches the router 22.

When the packet (11) Mr1r2a1a2 (I0) arrives at the router 22, the packet's source MAC address a1a2 and source IP address I2 are stored in the memory 1 (not shown), and then the packet's destination IP address I0 is stored. Reads the output port corresponding to and sends to that port. The packet is as shown in the figure by (12) IPI2I0 (IP indicates an IP address, I2 indicates the IP address of the source terminal 13-1, and I0 indicates the IP address of the destination server 20). and reaches the server 20.

Next, when the TCP mobile terminal 13-2 moves to the base station 12-2 and packet (13) Mr1r2a3a2 (I0) arrives at the base station 12-2, the packet is transferred to the destination base station. When the connected device 6-2 for adding, dropping, and passing packets is a device that connects to a base station in the direction toward the server 20 on the counterclockwise ring 1, this is a packet immediately after changing the destination base station. A signal gr indicating this is inserted into the packet, and the packet is sent to the packet add, drop, and pass device 6-2. When the packet from the TCP mobile terminal 13-2 reaches the add, drop, and pass device 6-2, the lower address memory specifies the lower address a2 of the source MAC address of the packet to send the packet outside the ring. 7, and the source MAC address of the packet is stored in the lower address memory 10 that specifies passage of the packet. The packet is transferred in the counterclockwise optical ring 1 by (14) Mr1r2a3a2gr (I0) as shown in the figure, and goes to the packet add, drop, and pass device 6-3.

When the packet (14) Mr1r2a3a2gr (I0) arrives at the packet add, drop, and pass device 6-3, the packet is a packet that has just moved from the base station and has a lower address a2 of the source MAC address of the packet. is not stored in the lower address memory 7 that specifies packet transmission outside the ring, so the packet is transferred in the counterclockwise optical ring 1 by (15) Mr1r2a3a2gr (I0) as shown in the figure, and sent to the vertex device 5. reach.
The packet that has arrived at the apex device 5 is sent out of the ring and reaches the router 22.

When the packet (16) Mr1r2a3a2gr (I0) arrives at the router 22, the source MAC address and source IP address of the packet are stored in the memory 1 (not shown in the figure), and then the destination IP address I0 of the packet is stored. Reads the output port to be used and sends data to that port. Although the packet (16) Mr1r2a3a2gr is given a signal gr indicating that the destination base station is a packet immediately after moving closer to the server, it is ignored and the IP packet of the packet is sent to the server 20. The packet (17) IPI3I0 (IP indicates an IP address, I3 indicates the IP address of the source terminal 13-2, and I0 indicates the IP address of the destination server 20) is transferred as shown in the figure. and reaches the server 20.

Next, when packet (18) IPI0I3 (IP indicates an IP address, I3 indicates the IP address of the terminal 13-2, and I0 indicates the IP address of the server 20) arrives at the router 22 from the server 20, , find the destination MAC address a3a2 of the pair of the destination IP address I3 of the packet from the first memory (not shown) or from the ARP table (not shown), convert it into a MAC packet, and convert the MAC packet (19) Ma3a2r1r2 Send (I3) to clockwise ring 2.

When the packet (20) Ma3a2r1r2 (I3) is transferred on the clockwise ring 2 and arrives at the packet add, drop, and pass device 6-3, the destination MAC address of the packet specifies the packet pass. Since the packet is not stored in the address table 8 and the lower address of the destination MAC address of the packet is not stored in the lower address memory 7 that specifies sending the packet outside the ring, the packet is sent to the front of the clockwise ring (21 ) Ma3a2r1r2(I3). When the packet arrives at the packet add, drop, and pass device 6-2, the destination MAC address of the packet is not stored in the address table 8 that specifies packet passage, and the destination MAC address of the packet is The lower address is stored in the lower address memory 7 that specifies packet transmission to the outside of the ring, and the lower address of the destination MAC address of the packet is stored in the lower address memory 10 that specifies the passage of the packet. The destination MAC address of the packet is stored in the address table 8 that specifies sending the packet outside the ring, the packet is copied, the copied packet is sent outside the ring as (22) Ma3a2r1r2(I3), and the original address is The packet is sent to clockwise ring 2 as (23) Ma3a2r1r2(I3). The base station 12-2 receives a UDP packet with a copy bit added from the packet add, drop, and pass device 6-2 to which the base station is connected, and the destination MAC address of the packet is not shown in the diagram. If stored in the MAC address table, the destination MAC address of the packet is designated as the source MAC address, and the packet adding, dropping, and passing device 6-2 specifies the passage of the packet. sends a packet to the ring network to delete from the address table. In the figure, a horizontal line is drawn to indicate that the MAC address a3a2 has been deleted from the address table 8 for specifying packet passage of the packet add, drop, and pass device 6-2.

Next, the packet from the terminal 13-1 passes through the packet add, drop, and pass device 6-1, as shown in the diagram by packet (24) Mr1r2a1a2(I0), and then passes through the packet add, drop, and pass device 6-1 (25) Mr1r2a1a2( I0), the packet is forwarded on the counterclockwise optical ring 1 to the packet add, drop and pass device 6-2. When the packet arrives at the packet add, drop, and pass device 6-2, the lower address a2 of the source MAC address of the packet is stored in the lower address memory 7 that specifies packet transmission outside the ring. Therefore, the source MAC address a1a2 of the packet is stored in the address table 8 that specifies passage of the packet. The storage of the source MAC address a1a2 is the storage of a new MAC address, and since the lower address a2, which is the same as the lower address of the MAC address a1a2, is stored in the lower address memory 10 that specifies the passage of the packet, the MAC The address a2 is erased, and the packet is transferred by (26) Mr1r2a1a2 (I0) through the counterclockwise optical ring 1 as shown in the figure, and is sent out toward the router 22. Erasure of the lower address a2 is indicated by a horizontal line in the figure.

Note that the destination MAC address a1a2 of the packet that arrived at the packet add, drop, and pass device 6-2 from the clockwise ring 2 is stored in the address table that specifies packet transmission outside the ring, and the destination of the packet is When the lower address of the MAC address is stored in the lower address memory that specifies packet transmission to the outside of the ring, and the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies the passage of the packet. may delete the lower address of the destination MAC address of the packet from the lower address memory that specifies passage of the packet.

Figure 1 shows the movement of a mobile terminal when the destination base station approaches the server, but conversely, when the destination base station moves away from the server, the packet immediately after moving via the destination base station becomes a packet. The packet arrives at the add, drop, and pass device in a counterclockwise ring, and the lower address of the source MAC address of the packet specifies the packet transmission out of the ring. If it is stored in the address memory 7, the lower address in the lower address memory is erased and the packet is directed to the server in a counterclockwise ring. In the above, when a mobile terminal moves between base stations, the address storage in the memory of the device for adding, dropping, and passing packets is deleted in the packet immediately after the movement. , when the mobile terminal changes the destination base station of the drop and pass device, when the packet passes through the add, drop and pass device of the packet that was sent outside the original ring, the increase occurs in the conventional method. This is to reduce the number of MAC addresses stored in the address table that specifies the passage of packets.

The lower address memory for specifying packet sending outside the ring of the device for adding, dropping, and passing packets in the ring network shown in FIG. 1 divides the lower address of the source MAC address of the packet into an upper part and a lower part, If one of the bit strings contains all bits 0, the MAC address is stored in a separate address table; otherwise, it is read from the position where multiple SRAM cells of the system LSI are addressed in the upper part. By storing the parallel data of the logical sum of each bit of the latch output of the parallel data and each bit of the parallel data obtained by decoding the lower part in the address specified position of the plurality of SRAM cells, the lower address of the source MAC address is stored. A memory that inserts and stores the lower part of the decode bit 1 at the bit 1 position of the decode as bit 1 meaning lower address storage,
When deleting the lower address of the source MAC address from the lower address memory that specifies sending packets outside the ring, delete the lower address memory that specifies sending packets outside the ring with the upper part of the lower address of the source MAC address. A latch signal of the parallel data is output from the ring by ANDing each bit of the parallel data read from the addressed position and the bit inversion bit of each bit of the parallel data decoded from the lower part of the lower address of the source MAC address. By storing the lower part of the lower address of the source MAC address in the address specified position of the lower address memory that specifies packet transmission, insert bit 0 into the bit 1 position of decoding as bit 0, which means that the lower address is not stored. A lower address memory for specifying packet adding, dropping, and passing of a packet to outside the ring of a ring network or a tree-like ring network of a packet transfer system characterized by storing the packet.

The configuration method of the lower address memory mentioned above is based on "Only the originating terminal address" in Communication method vol 113 No, 207, September 12-13, 2013 of IEICE Technical Report CS2013-28-CS2013-40. This is disclosed in Chapter 3, ``Address storage method using data storage areas as addresses'' on page 44 of ``Proposal of MAC-operated tree-like ring network that transfers packets in both directions''. It is also disclosed in Japanese Patent Application Laid-open No. 2019-097045 (address memorization method). This method can also be configured as shown in FIG.
In FIG. 2, storage of a lower address and erasure of a lower address are switched and operated under the control of a bit 0 write signal (H) which is a signal for erasing a lower storage address. To store/erase the lower address, the 32 bits of parallel data at the position specified by the upper part (17 bits) of the lower address of the MAC address is taken into the logic circuit, and the lower part (5 bits) of the lower address of the MAC address is stored in the SRAM. The 32-bit parallel data resulting from the calculation with the decoded signal is written to the SRAM again. The logic circuit is composed of a small LSI, FPGA, or ASIC, and uses external SRAM.

1 Subscriber system counterclockwise optical ring
2 Subscriber system clockwise optical ring 5 Vertex devices 6-1, 6-2, 6-3 Device for adding, dropping, and passing packets 7 Lower address memory 8 for specifying packet transmission outside the ring Address table 10 for specifying Lower address memory 12-1, 12-2, 12-3 for specifying packet passage Base stations 13-1, 13-2, 13-3, 13-4 Mobile terminal 14 Mobile terminal movement 20 Server 22 Router

Claims (3)

A wireless base station is accommodated in a ring network or the lowest ring of a tree-shaped ring network, and a mobile terminal under the wireless base station receives Ethernet other than OAM packets arriving from the clockwise ring of the ring network or tree-shaped ring network. Communicate TCP or UDP MAC packets with a server connected via a router to a vertex device that blocks the passage of packets transferred using only the MAC address part of NetFrame (registered trademark) or IPv6 addresses (hereinafter referred to as MAC packets). A packet transfer system that enables mobile terminals in a network to move between the wireless base stations, the system comprising:
When a MAC packet from the mobile terminal via a base station arrives at a packet adding, dropping, and passing device of the ring network or tree-shaped ring network,
If the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets to which the destination base station is connected is a device in the direction away from the server on the counterclockwise ring,
The device for adding, dropping, and passing packets stores the lower address of the source MAC address of the packet in the lower address memory that specifies the sending of the packet outside the ring, and sends the packet from the address table that specifies the passing of the packet. If the original MAC address is deleted and the packet is sent to the server via the apex device in a counterclockwise ring, and the packet arrives at the device that adds, drops, and passes the packet, the packet is sent out of the ring. deleting the lower address of the source MAC address of the packet from a lower address memory specifying the packet, and directing the packet to the server via the apex device in a counterclockwise ring;
On the other hand, if the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets connected to the destination base station is the device approaching the server on the counterclockwise ring. ,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring of the device for adding, dropping, and passing the packet, and the lower address of the source MAC address of the packet is stored as the lower address of the packet. A lower address specifying the pass is stored in memory to direct said packet through the apex device in a counterclockwise ring to the server, and when the packet arrives at the packet add, drop, and pass device, it is If the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission, the source MAC address of the packet is stored in the address table that specifies the passage of the packet, and the packet to the server via the apex device in a counterclockwise ring;
Furthermore, if the packet is not a packet immediately after moving to the destination base station,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies the sending of the packet outside the ring of the device for adding, dropping, and passing the packet, and the packet is sent to the server via the apex device in the counterclockwise ring. When the packet arrives at a device for adding, dropping, and passing packets, the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission outside the ring. In this case, the source MAC address of the packet is stored in an address table that specifies passage of the packet, and if the source MAC address is stored as a new MAC address, and the source MAC address of the packet is if a lower address of is stored in a lower address memory specifying passage of the packet, means for erasing the lower address and directing the packet to the server via the apex device in a counterclockwise ring;
Packets other than the communication start packet, such as an incoming voice call packet, an SMS (Short Message Service) packet, or the first incoming FTP packet from the server, arrive at a device for adding, dropping, and passing packets in a clockwise ring. if you did this,
If the destination MAC address of the packet is stored in an address table that specifies passage of the packet, the packet is sent toward a device for adding, dropping, and passing the packet in front of the clockwise ring. , the destination MAC address of the packet is not stored in an address table that specifies the passage of the packet, and the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies the passage of the packet. and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, copy the packet and send the copied packet outside the ring. , sending the original packet towards a forward packet add, drop and pass device of the clockwise ring;
In cases other than the above, and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, the packet is sent outside the ring, and In this case, a packet transfer system comprising means for transmitting the packet toward a device for adding, dropping, and passing packets forward of the clockwise ring.
A lower address memory for specifying packet sending out of the ring of a device for adding, dropping, and passing packets in a ring network or a tree-like ring network of a packet transfer system according to claim 1, wherein the memory includes a source MAC address of a packet. The lower address of is divided into an upper part and a lower part, and if either of the bit strings contains all bits 0, a separate address table is used. By storing the parallel data of the logical sum of each bit of the latch output of the parallel data to be read and each bit of the parallel data obtained by decoding the lower part in the address specified position of the SRAM cell, the lower part of the source MAC address is stored. A memory that inserts and stores the lower part of the address with bit 1 at the bit 1 position of decoding as bit 1 meaning lower address storage,
When deleting the lower address of the source MAC address from the lower address memory that specifies sending packets outside the ring, delete the lower address memory that specifies sending packets outside the ring with the upper part of the lower address of the source MAC address. A latch signal of the parallel data is output from the ring by ANDing each bit of the parallel data read from the addressed position and the bit inversion bit of each bit of the parallel data decoded from the lower part of the lower address of the source MAC address. By storing the lower part of the lower address of the source MAC address in the address specified position of the lower address memory that specifies packet transmission, insert bit 0 into the bit 1 position of decoding as bit 0, which means that the lower address is not stored. A lower address memory for specifying packet adding, dropping, and passing of a packet outside the ring of a ring network or a tree-like ring network of a packet transfer system, characterized in that it stores packets outside the ring.
A wireless base station is accommodated in a ring network or the lowest ring of a tree-like ring network, and a mobile terminal under the wireless base station receives MAC packets other than OAM packets arriving from the clockwise ring of the ring network or tree-like ring network. A packet transfer method that enables movement of a mobile terminal between the wireless base stations in a network that communicates TCP or UDP MAC packets with a server connected via a router to an apex device that blocks passage of packets, the method comprising:
When a MAC packet from the mobile terminal via a base station arrives at a packet adding, dropping, and passing device of the ring network or tree-shaped ring network,
If the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets to which the destination base station is connected is a device in the direction away from the server on the counterclockwise ring,
The device for adding, dropping, and passing packets stores the lower address of the source MAC address of the packet in the lower address memory that specifies the sending of the packet outside the ring, and sends the packet from the address table that specifies the passing of the packet. If the original MAC address is deleted and the packet is sent to the server via the apex device in a counterclockwise ring, and the packet arrives at the device that adds, drops, and passes the packet, the packet is sent out of the ring. deleting the lower address of the source MAC address of the packet from a lower address memory specifying the packet, and directing the packet to the server via the apex device in a counterclockwise ring;
On the other hand, if the packet is a packet that has just been transferred to the destination base station where the device for adding, dropping, and passing packets connected to the destination base station is the device approaching the server on the counterclockwise ring. ,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring of the device for adding, dropping, and passing the packet, and the lower address of the source MAC address of the packet is stored as the lower address of the packet. A lower address specifying the pass is stored in memory to direct said packet through the apex device in a counterclockwise ring to the server, and when the packet arrives at the packet add, drop, and pass device, it is If the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission, the source MAC address of the packet is stored in the address table that specifies the passage of the packet, and the packet to the server via the apex device in a counterclockwise ring;
Furthermore, if the packet is not a packet immediately after moving to the destination base station,
The lower address of the source MAC address of the packet is stored in the lower address memory that specifies the sending of the packet outside the ring of the device for adding, dropping, and passing the packet, and the packet is sent to the server via the apex device in the counterclockwise ring. When the packet arrives at a device for adding, dropping, and passing packets, the lower address of the source MAC address of the packet is stored in the lower address memory that specifies packet transmission outside the ring. In this case, the source MAC address of the packet is stored in an address table that specifies passage of the packet, and if the source MAC address is stored as a new MAC address, and the source MAC address of the packet is if a lower address of is stored in a lower address memory specifying the passage of the packet, clearing the lower address and directing the packet through the apex device in a counterclockwise ring to the server;
Packets other than the communication start packet, such as an incoming voice call packet, an SMS (Short Message Service) packet, or the first incoming FTP packet from the server, arrive at a device for adding, dropping, and passing packets in a clockwise ring. if you did this,
If the destination MAC address of the packet is stored in an address table that specifies passage of the packet, the packet is sent toward a device for adding, dropping, and passing the packet in front of the clockwise ring. , the destination MAC address of the packet is not stored in an address table that specifies the passage of the packet, and the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies the passage of the packet. and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, copy the packet and send the copied packet outside the ring. , sending the original packet towards a forward packet add, drop and pass device of the clockwise ring;
In cases other than the above, and if the lower address of the destination MAC address of the packet is stored in the lower address memory that specifies sending the packet outside the ring, the packet is sent outside the ring, and In this case, a packet forwarding method comprising the step of transmitting the packet toward a forward packet adding, dropping, and passing device in a clockwise ring.