JPH1117739A - Frame relay router and frame relay communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fluctuation in the delay of data by transmitting a non- priority FR frame with throughput based on registered certification information velocity, guaranteed burst quantity and over burst quantity when a priority FR(frame relay) frame is not transmitted for a prescribed time, and transmitting the non-priority FR frame in subtracted bands when the priority FR frame is transmitted. SOLUTION: A DLCI registration table 10a stores the maximum frame size of the priority FR frame and stores the certification information and the guaranteed and over burst quantities preferentially for an FR frame for voice and non-preferentially for an FR frame for data. A transmission frame monitoring part 10c monitors the state of a frame relay network and monitors the transmission rate of the transmission frame or the like so as to guarantee the certification information, guaranteed burst quantity and over burst quantity registered in the DLCI registration table 10a. Based on the result of transmission frame monitor, a frame transmission control part 10d selectively transmits the FR frame to be transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data link connection identifier (DLCI:
The present invention relates to a frame relay router or a frame relay communication device that registers a priority for service quality for each Data Link Connection Identifier, and performs transmission control with the registered service quality.

[0002]

2. Description of the Related Art FIG.
FIG. 10 illustrates an example of a conventional inter-LAN connection and DLCI registration table by the frame relay network shown in FIG. 07762, in which routers 50a, 50b, and 50c are connected to a plurality of terminals 70a on the LANs 60a, 60b, and 60c.
Multiplex the frames from the routers 50a to 50d.
b and 50c are communicated via the frame relay network. A PVC (Permanent Virtual Circui) whose destination is identified by a data link connection identifier (DLCI) between the routers 50a and 50b and 50c.
t) is set.

For example, a terminal 70a on a LAN 60a and an L
When communication is performed between the terminals 70c on the AN 60b, the LAN frame transmitted from the terminal 70a and addressed to the terminal 70c is indicated by the router 50a indicating that the LAN frame is addressed to the router 50b.
The LAN frame is encapsulated in the frame of the frame relay network (FR frame) by LCI # 1, and is transferred onto the frame relay network. The LAN frame addressed to the terminal 70a transmitted from the terminal 70c has a router D indicating that the LAN frame is addressed to the router 50a.
It is encapsulated in an FR frame by LCI # 2 and transferred on a frame relay network. Similarly, LA
Terminal 70b on N60a and terminal 70d on LAN60c
When communication is performed between the LAN frames, the LAN frame is encapsulated in the FR frame by the DLCI # 3 indicating that the router 50c is addressed to the router 50c and the DLCI # 4 indicating that the router 50c is addressed to the router 50a. Here, DLCI # 1 and DLCI # 2 and DLCI # 3 and DLCI # 4 need not be the same value, and DLCI # 1
And DLCI # 2 and DLCI # 3 and DLCI # 4 are managed in the frame relay network 100.

In each router, the registered DLC
Committed Information Rat (CIR)
e), guaranteed burst amount (Bc: Commited Burst Size), excess burst amount (Be: Excess Burst Size) and maximum frame length for each frame relay interface are specified,
The router performs frame transmission control according to the specified value. For example, in the router 50a, CIR # 1, Bc # 1 and Be # 1 for DLCI # 1, and DLCI # 3
, CIR # 3, Bc # 3 and Be # 3 are set. That is, when the LAN frame is received by the router, if the frame relay network is not in a congestion state, the FR frame is transmitted at a throughput determined by CIR, Bc, and Be. Is suppressed. Since the LAN speed is higher than the line speed of the frame relay interface, the transfer frame is stored in a transmission buffer in the router and then transferred to the frame relay interface.

[0005] In general, a plurality of data links identified by DLCI are set on one frame relay interface, and C is registered for each data link.
Since the sum of IRs usually exceeds the link bandwidth of a physical line, when transmission of an FR frame occurs on a plurality of data links, transmission control is performed inside the router regardless of the congestion state of the frame relay network.

For example, when no congestion occurs in the frame relay network and the router, the router processes the LAN frames in the order of arrival. However, as shown by the router 50d in FIG. 11, in a configuration in which the router has a plurality of LAN-side interfaces and multiplexes to a single frame relay interface, the contention of LAN frames from each LAN-side interface may occur. There is. For example, as shown in FIG.
N frame 20a (for example, L frame from terminal 70e in FIG. 11)
AN frame) and the LAN frame 20b (for example, FIG.
If the LAN frame from the terminal 70f of this device competes with the router (for example, the router 50d in FIG. 11), the router transmits the LAN frame (here, the LAN frame 20a) that has arrived at the router first, and the transmission of the LAN frame 20a is not performed. After the completion, the LAN frame 20b is transmitted. When viewed from the LAN frame 20b, a delay occurs during the transmission of the LAN frame 20a. Here, the router encapsulates the LAN frame received from the LAN side into an FR frame and transmits the frames (20a and 20b) on the frame relay interface. When the frame relay router receives an FR frame from the frame relay network, the frame is processed in the order of the received FR frame and transferred to the LAN according to the DLCI value of the received FR frame.

The communication of the terminals on the LAN when the network is constructed by the frame relay router has been described above with reference to FIG. 11, but as shown in FIG.
Even when the router located at the first router 50a is the frame relay communication device 51a, the frame relay communication device 51a transmits a frame from a terminal connected to the communication device, and the frame relay router transmits a LAN frame. Similarly to the transfer, it is transferred to the frame relay network as an FR frame. Also, FR frames received from the frame relay network are processed in the order of the received FR frames, and like the frame relay router,
It is transferred to the connected terminal according to the value of the DLCI of the received FR frame.

[0008]

In the above-described conventional router, since LAN frames addressed to a plurality of destinations are multiplexed, when communication occurs simultaneously, the LAN frames are accumulated in a buffer in the router, Transmission delay occurs. If the data to be communicated is data that does not require real-time properties such as file transfer, the fluctuation of the transmission delay does not matter. However, in recent years, there are services and the like that require real-time properties, such as Internet telephones.
For such a service, it is necessary to provide a priority and perform frame transmission control so as to reduce fluctuation of transmission delay.

In the transfer of a data frame such as a file transfer, the data frame is efficiently converted to an FR.
For encapsulation into frames, it is desired that the maximum frame size on the frame relay network be a relatively long value (eg, 1000 octets or more). However, when there are frames having severe real-time characteristics such as audio frames, a short frame size (for example, 128 to 256 octets) is desired in order to shorten the frame waiting (transmission delay) time in the event of frame conflict. This is contrary to the efficiency of data frame transfer.

[0010] Further, due to the frame transmission control in the frame relay router, a LAN frame received from the LAN side is queued in a transmission buffer in the frame relay router, causing a transmission delay. However, rather than discarding frames for which a real-time property such as a voice frame is queued in the transmission buffer and transmitted in the presence of a large delay, discarding a voice frame with a delay of a certain time or more is more effective. May be preferred for the user.

A first object of the present invention is to solve the above-described problems. A first object of the present invention is to provide a CIR reserved for the DLCI for handling the audio frame by using a CIR reserved for the DLCI. An object of the present invention is to transmit a data such as a frame, which is easily affected by a delay, with a small fluctuation of the delay.

A second object is to reduce the fluctuation of the delay of the voice frame even when the voice frame and the data frame coexist, and when the voice frame is not transmitted,
An object of the present invention is to efficiently transmit a data frame.

A third object of the present invention is to prevent an invalid FR frame from being transferred to a frame relay network by discarding the remaining related FR frames when a discarded FR frame of a LAN frame is discarded. And

A fourth object of the present invention is to discard the FR frame for voice if it has been kept in the transmission buffer inside the router for a time limit or more.

[0015]

A frame relay router according to a first aspect of the present invention relays a priority frame and a non-priority frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner. DLCI registration means for registering priority / non-priority, authorized information rate, guaranteed burst amount, and excess burst amount corresponding to a DLCI identifier for identifying a communication partner of a frame relay frame (hereinafter, FR frame) in the router; Receiving a frame (hereinafter, a LAN frame) from the local area network,
L divided into the above FR frames and stored in the transmission buffer
AN frame receiving means, transmission frame monitoring means for monitoring transmission traffic of a priority FR frame or non-priority FR frame based on a DLCI identifier for identifying a communication partner held in the FR frame, and transmission frame monitoring means for monitoring the transmission frame. Frame transmission control means for controlling transmission of the FR frame according to the monitoring result of the means, and frame relay transmission means for transmitting the FR frame stored in the transmission buffer to the frame relay network under the control of the frame transmission control means The frame transmission control means, if the priority frame is not transmitted for a predetermined time as a result of the monitoring of the transmission frame monitoring means, the non-priority FR frame, the registered authorized information rate, the guaranteed burst amount, Transmit at a throughput based on the amount of excess burst, and If the priority FR frame is transmitted within the time, the priority FR frame is transmitted at the throughput based on the registered committed information rate, the guaranteed burst amount, and the excess burst amount, and the non-priority FR frame is transmitted to the frame relay interface. The transmission rate is controlled so that transmission is performed in a band obtained by subtracting the authorized information rate, the guaranteed burst amount, and the throughput based on the excess burst amount registered in the priority frame from the link band of the physical link line.

A frame relay communication apparatus according to a second invention is a frame relay communication apparatus for relaying priority data and non-priority data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner. DLCI that identifies the communication partner of the
DLCI registration means for registering priority / non-priority, authorized information rate, guaranteed burst amount, and excess burst amount corresponding to an identifier, and communication for receiving data from a communication terminal, dividing the data into the above FR frames, and storing the FR frames in a transmission buffer Data reception means, transmission frame monitoring means for monitoring transmission traffic of a priority FR frame or non-priority FR frame based on a DLCI identifier for identifying a communication partner held in the FR frame, and transmission frame monitoring means Frame transmission control means for controlling transmission of the FR frame, and frame relay transmission means for transmitting the FR frame stored in the transmission buffer to a frame relay network under the control of the frame transmission control means, based on the monitoring result of Has the above-mentioned frame transmission control means,
The monitoring result of the transmission frame monitoring means, a predetermined time priority F
If the R frame is not transmitted, the non-priority FR frame is transmitted at a throughput based on the registered committed information rate, the guaranteed burst amount, and the excess burst amount. If the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is transmitted. A priority FR frame is transmitted at a throughput based on the registered committed information rate, guaranteed burst amount, and excess burst amount, and a non-priority FR frame is registered in the priority frame from the link band of the physical link line of the frame relay interface. The transmission rate is controlled so that transmission is performed in a band obtained by subtracting the throughput based on the approved information rate, the guaranteed burst amount, and the excess burst amount.

A frame relay router according to a third invention is a frame relay router for relaying a priority frame and a non-priority frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner. The first maximum frame length is assigned to the priority FR frame corresponding to the DLCI identifier identifying the communication partner, and the second maximum frame length is assigned to the non-priority FR frame.
Frame length registering means for registering the maximum frame length, LAN frame receiving means for receiving a LAN frame from the local area network, dividing the FR frame into FR frames, and storing the divided FR frames in a transmission buffer, and holding the LAN frame in the FR frame. Transmission frame monitoring means for monitoring whether or not a priority FR frame or a non-priority FR frame is transmitted based on a DLCI identifier for identifying a communication partner, and transmitting the FR frame stored in the transmission buffer to the frame relay network. The LAN frame receiving means, based on the result of the monitoring by the transmission frame monitoring means, within a predetermined time.
If the R frame is not transmitted, the non-priority FR frame is divided into the second maximum frame length, and if the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is divided into the second maximum frame length. It is divided within the first maximum frame length shorter than the length and stored in the transmission buffer.

A frame relay communication device according to a fourth invention is a frame relay communication device for relaying priority data and non-priority data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner. DLCI that identifies the communication partner of the
Frame length registration means for registering a first maximum frame length in a priority FR frame and a second maximum frame length in a non-priority FR frame corresponding to an identifier; receiving data from the communication terminal; Communication data receiving means for dividing and storing in a transmission buffer, and a transmission frame for monitoring the transmission of a priority FR frame or a non-priority FR frame based on a DLCI identifier for identifying a communication partner held in the FR frame Monitoring means, and frame relay transmitting means for transmitting the FR frame stored in the transmission buffer to the frame relay network, wherein the communication data receiving means receives a result of monitoring by the transmission frame monitoring means within a predetermined time. If the priority FR frame is not transmitted to the second maximum If the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is divided into a first maximum frame length shorter than a second maximum frame length and is transmitted to the transmission buffer. What to store.

According to a fifth aspect of the present invention, there is provided a frame relay router for relaying a frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner. Receiving means, a dividing means for dividing the received LAN frame into FR frames, a queuing means for associating the divided FR frames with one another in a transmission buffer, and a queuing in the transmission buffer. When discarding a given FR frame from the transmission buffer, the discarding unit discards the FR frame associated with the FR frame.

A frame relay communication apparatus according to a sixth invention is a frame relay communication apparatus for relaying data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner. Communication data receiving means, receiving means for dividing the received communication data into FR frames, queuing means for associating the divided FR frames with each other in a transmission buffer, and queuing in the transmission buffer. When discarding a given FR frame from the transmission buffer, the discarding unit discards the FR frame associated with the FR frame.

A frame relay router according to a seventh invention is a frame relay router for relaying a frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner. LAN frame receiving means, receiving means for dividing the received LAN frame into FR frames, and setting a timer corresponding to the divided FR frames,
It has queuing means for queuing in the transmission buffer, and discarding means for discarding the FR frame when a timer corresponding to the FR frame has passed a predetermined time or more after being queued.

According to an eighth aspect of the present invention, there is provided a frame relay communication apparatus for relaying data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner. Communication data receiving means for receiving the communication data; dividing means for dividing the received communication data into FR frames; queuing means for setting a timer corresponding to the divided FR frames and queuing in the transmission buffer; If the timer corresponding to the FR frame has elapsed for a predetermined time or more after that, the discard means for discarding the FR frame is provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. In the present embodiment, in order to reduce the delay fluctuation of the audio frame, when the audio frame is present, the authorized information rate C reserved for the audio FR frame is used.
The audio frame is preferentially handled in the IR. Here, a voice frame or a data frame from the LAN is called a LAN frame, and a frame to the frame relay network is called an FR frame. FIG. 1 shows a configuration diagram of a frame relay router that encapsulates a LAN frame into an FR frame and relays the FR frame to a frame relay network.

In FIG. 1, reference numeral 10a denotes a DLCI registration table, which gives priority to a FR frame for voice in accordance with DLCI.
The data FR frame is given non-priority, the maximum frame size of the priority FR frame is stored, and CIR and Bc are stored.
And Be are stored. 10i is a LAN frame receiving unit,
Receives LAN frames from the local area network and segments them into FR frames. Reference numeral 10b denotes a transmission buffer for storing the segmented transmission FR frames, and a transmission hold queue for queuing the transmission FR frames for each registered DLCI. Reference numeral 10c denotes a transmission frame monitoring unit which monitors the state of the frame relay network and transmits the transmission rate of the transmission FR frame so as to guarantee the authorized information rate CIR, the guaranteed burst amount Bc, and the super burst amount Be registered in the DLCI registration table 10a. Monitor etc.

Reference numeral 10d denotes a frame transmission control unit which transmits F from the transmission buffer based on the result of the transmission frame monitoring unit.
An R frame is selected, and an FR frame is transmitted. Further, 10f is a reception buffer for storing the received FR frame, 10j is an FR frame receiving unit, and 10g is a received frame monitoring unit, which monitors the state of the frame relay network from the received FR frame. Reference numeral 10h denotes a frame reception control unit which controls the FR frame received by the reception buffer. A LAN router 10e transfers a LAN frame received from the LAN to the frame relay network and an FR frame received from the frame relay network to the LAN. FIG. 2 shows a configuration diagram of a frame relay communication device that performs communication processing via a frame relay network.
10a is a DLCI registration table, 10i is a communication data receiving unit, 10b is a transmission buffer, 10c is a transmission frame monitoring unit, and 10d is a frame transmission control unit. Also, 10
f is a reception buffer, 10j is an FR frame reception unit, 10j
g is a reception frame monitoring unit, 10h is a frame reception control unit, and 11e is a communication processing control unit for controlling the connected terminal. The main difference from the frame relay router is that the frame relay communication device does not have a router unit.

FIG. 3 shows an example of the DLCI registration table 10a. The router 50a in the network configuration example shown in FIG.
3 is a DLCI registration table. FIG. 4 shows a frame relay interface of the router 50a for voice and data F.
FIG. 9 is a diagram illustrating a situation in which an R frame is being transferred. That is, in the section 5a (non-voice section), the FR frame is not transferred on the DLCI # 1 registered as the voice FR frame, and is transmitted only on the DLCI # 3 registered as the data FR frame. An example in which transfer is performed is shown. In section 5b (voiced section),
An example in which an FR frame is transferred on DLCI # 1 and DLCI # 3 is shown. The transmission frame monitoring unit 10c monitors the state of the frame relay interface separately into a section where the data FR frame is transferred and a section where the voice FR frame is transferred. Note that if no audio FR frame is transmitted after a predetermined time Tx has elapsed from the transfer of the last FR frame on DLCI # 1 registered as an audio FR frame, a transition is made from section 5b to section 5a. The time Tx depends on the sum of the CIRs set in the DLCI registered as the voice FR frame, and is used to recognize the end of the voice call.

When the transmission frame monitoring unit 10c recognizes that the transmission frame monitoring unit 10c is the section 5a (non-voice section) in FIG. 4, the frame transmission control unit 10d sets the FR on the DLCI # 3 registered as the data FR frame. When transmitting a frame, the CIR # 3, Bc # 3, and Be # 3 set for the DLCI # 3 are used to transmit the CIR #.
3, the data frame received from the LAN is encapsulated in an FR frame at a throughput determined by Bc # 3 and Be # 3 and transmitted to the frame relay network. On the other hand, when the transmission frame monitoring unit 10c recognizes that it is the section 5b in FIG. 4, the frame transmission control unit 10d transmits the D frame registered as the voice FR frame.
The FR frame on LCI # 1 is a frame with a throughput determined by CIR # 1, Bc # 1 and Be # 1 according to CIR # 1, Bc # 1 and Be # 1 set for the DLCI # 1. Perform transmission processing to the relay network. At this time, the FR frame on DLCI # 3 registered as the data FR frame is the DLCI # 3
DLCI # 1 registered as a voice FR frame from the link band R of the physical link line of the frame relay interface, regardless of the presence or absence of a congestion notification from the frame relay network for the DLCI The transmission processing is performed within the link band (R-CIR # 1) in which the total sum of CIR # 1 set in # 1 is reduced.

For example, CIR # 3, Bc # 3 and Be #
If the throughput determined in Step 3 is within R-CIR # 1, the transmission is performed at the throughput.
Is exceeded, the data is transmitted at the transfer rate of R-CIR # 1. As described above, the DLC that transfers the data FR frame according to the presence or absence of the prioritized voice FR frame.
Since the transfer rate on I is controlled, it is possible to preferentially secure a band for the voice FR frame without providing a complicated buffer control mechanism. In the above example, LAN
In the example shown above, an FR frame is edited from a frame for voice and data from and transmitted to a frame relay network, but a voice terminal and a data terminal are connected to a communication device,
The frame relay communication device may edit the voice and data from each terminal into an FR frame and send it to the frame relay network.

Embodiment 2 In this embodiment, when a voice frame is received from the LAN and there is a voice frame to be transmitted to the frame relay network, the maximum frame size for encapsulating the voice frame into the FR frame is reduced to reduce the transmission waiting time. Shorten. And L
If a frame for data is received without receiving a frame for voice from the AN, and there is a frame for data to be transmitted to the frame relay network, increase the maximum frame size for encapsulating the frame for data in the FR frame. Thus, efficient communication can be performed.

As in the first embodiment, in section 5a of FIG.
If no FR frame has been transmitted on # 1, DL
The voice frame received from the LAN side with the maximum frame size FM1 for the data FR frame registered in the CI registration table 10a is encapsulated in the FR frame. On the other hand, when the FR frame is transmitted on the DLCI # 1 registered as the audio FR frame in the section 5b, the maximum frame size for the audio FR frame registered in the DLCI registration table 10a as shown in FIG. The FM2 converts the voice or data frame 6a received from the LAN side into FR frames 6a1 and 6a.
2 and 6a3. That is, even if the maximum frame size FM1 is registered in the DLCI registration table 10a of the data FR frame, the data frame from the LAN is encapsulated with the maximum frame size FM2.

The transmission buffer 10b is queued in the FR frame, and the frame transmission controller 10d transmits the head frame of the transmission suspension queue of the DLCI based on the instruction of the transmission frame monitor 10c. For example, when transmitting the voice frame 6a from the LAN in FIG. 6 to the frame relay network, the FR frame 6a
Transmission of 1, 6a2 and 6a3 is performed at different timings. In the above, the LAN in the frame relay router
Frame transfer by changing the maximum frame size when transferring the LAN frame received from the side to the frame relay network has been described, but the frame relay communication device similarly transfers the frame received from the connection terminal to the frame relay network. Figure 5
The maximum frame size for encapsulating the frame received from the terminal into the FR frame is changed depending on the section 5a and the section 5b. As described above, since the transfer of the frame to the frame relay network is performed in units of the FR frame, even when the voice frame and the data frame compete with each other, the FR frame of the maximum frame size FM2 is transmitted at the maximum. , And it is possible to satisfy the transmission delay time and fluctuation desired by the audio frame. Further, when there is no voice frame, the data frame is processed with a relatively long maximum frame size FM1, so that the frame relay router receives the data frame from the LAN and the frame relay communication device receives the data frame from the connection terminal. The frame to be received is less likely to be fragmented into a plurality of FR frames, and the overhead due to the fragmentation is reduced, enabling efficient transfer.

Embodiment 3 FIG. In the second embodiment, the example in which the maximum frame size on the frame relay network is changed depending on the presence or absence of the voice frame has been described.
An example of a process when the data frame is fragmented into a plurality of FR frames, and the FR frames are discarded from the transmission buffer after being held in the transmission buffer by the frame transmission control will be described below.

For example, the data frame received from the LAN in the section 5b of FIG. 5 is fragmented into a plurality of FR frames as shown in FIG. The transmission buffer 10 adds an association (pointer) to an area indicating that the frame is a fragmented FR frame.
Queue in the transmission hold queue for each DLCI in b. FIG. 8 shows an example of a transmission hold queue for DLCI # 3, and shows LAN frames 7a1, 7a2 and 7a.
3 is queued in the transmission hold queue and the LAN
When the frame 7a1 is queued as an FR frame, the FR frames 7a1-1, 7a1-2, and 7a-
3 fragmented.

For example, in a frame relay router, LA
If the race condition of the LAN frame received from the N side continues for an excessively long time, the transmission buffer 10b inside the router overflows,
Transmission frame discard control is required. In this case, there is a method of discarding the frames queued in the transmission buffer and storing the received LAN frame in the transmission buffer, or discarding the LAN frame received after the transmission buffer overflows. In the present embodiment, the transmission buffer 1
An example will be described in which frames are discarded in the order queued in 0b. In the frame relay router, the first FR frame queued in the transmission buffer in FIG.
a1-1, and discards the FR frame 7a1-1.
At this time, as the FR frame related to 7a1-1, 7a1
-2, and 7a1-3 as the FR frame related to 7a1-2, the FR frame 7a1
-1 when discarding FR frames 7a1-2 and 7a1-3
At the same time.

As described above, when at least one FR frame among the LAN frames fragmented into FR frames is discarded, the subsequent fragmented FR frames are also discarded at the same time. Since a part of the FR frame is prevented from being transferred to the frame relay network, the frame relay network can be used efficiently. In the above example, the transmission control in the case of the contention of the received LAN frame in the frame relay router has been described. However, the same processing is performed in the frame relay communication device when the contention of the received frame from the connected terminal occurs. .

Embodiment 4 FIG. In the above-described third embodiment, an example is described in which the FR frame is discarded after the data frame is fragmented into a plurality of FR frames and held in the transmission buffer. An example of a process when the FR frame is discarded from the transmission buffer when the FR frame of the transmission frame exceeds the time limit in the transmission waiting time is described below.

For example, section 5a and section 5 in FIG.
Regardless of b, D registered as a voice FR frame
When suspending the FR frame on the LCI in the transmission buffer 10b, an area for registering the time (time stamp) queued in the transmission buffer is provided in the transmission buffer as shown in FIG. DLC in transmit buffer
The transmission hold queue for each I is queued in chronological order. In FIG. 9, the FR frames 8a1, 8a2 and 8a
3 is queued in the transmission buffer. The frame transmission control unit 10d refers to the time stamp registered in the first pending frame of the transmission pending queue of the DLCI in which transmission is suspended at regular intervals, and elapses a prescribed time To or more from the registered time. If so, discard the frame. In FIG. 9, the first FR frame (8a1) is stored in the transmission hold queue at time stamp T1, and 8a2 and 8a3 are stored in the queue at time stamps T2 and T3, respectively. The frame transmission control unit 10d sets the time stamp T4 (T1 + To <
When referring to the transmission buffer at T4 <T2 + To>, the FR frame 8a1 is discarded.

DL registered as audio FR frame
Since the FR frame on the CI is not transmitted within the router with a delay equal to or longer than the specified time To, it is possible to improve the quality when sound is reproduced on the receiving side.

[0039]

As described above, according to the present invention, in a frame relay communication device or router accommodating traffic such as voice, priority is given to processing of traffic such as voice, and the maximum frame size on the frame relay interface. Is changed depending on the presence or absence of traffic such as voice, so that the delay of traffic such as voice can be reduced, and the traffic of data when there is no traffic such as voice can be efficiently processed. Furthermore, when normal traffic is fragmented and transmitted when traffic such as voice is present, the relevant FR frame is simultaneously discarded when the fragmented FR frame is discarded, thereby increasing the effective throughput of the frame relay network. Can be improved. Further, by providing a time stamp when the traffic such as voice is held in the device, the voice quality can be improved by suppressing the delay within a certain time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating functions of a frame relay router according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating functions of a frame relay communication device according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a DLCI registration table according to an embodiment of the present invention.

FIG. 4 DLCI on frame relay interface
It is a figure which shows the presence or absence of FR frame transfer for every.

FIG. 5 is a diagram showing the presence or absence of FR frame transfer for each DLCI on the frame relay interface when changing the maximum frame size based on the presence or absence of voice data.

FIG. 6 is a diagram showing frame division when fragmented when encapsulating a LAN frame into an FR frame.

FIG. 7 is a diagram showing frame division when a frame from a terminal is fragmented when encapsulating the frame.

FIG. 8 is a diagram illustrating queuing of a fragmented FR frame into a transmission hold queue.

FIG. 9 is a diagram illustrating queuing of a voice frame to a transmission hold queue.

FIG. 10 is a diagram illustrating a configuration example when communication is performed via a frame relay network.

FIG. 11 is a configuration diagram when communication is performed via a conventional frame relay network.

FIG. 12 is a configuration diagram including a frame relay communication device when performing communication via a conventional frame relay network.

FIG. 13: Multiple LAs in a frame relay router
FIG. 9 is a diagram showing a frame flow when N frames are multiplexed and an FR frame is transmitted to a frame relay interface.

[Explanation of symbols]

5a Section in which only FR frames in which data frames are encapsulated flow 5b Section in which FR frames in which voice frames are encapsulated flow 6a LAN frames 6a1 to 6a3 FR frames in which LAN frames 6a are encapsulated 6b Terminals Frame from 7a1 to 7a3 Frame for data 7a1-1 to 7a1-3 FR frame encapsulating data frame 7a1 7a2-1 FR frame encapsulating data frame 7a2 7a3-1 Frame for data 7a3 encapsulated FR frame 8a1 to 8a3 FR frame encapsulating voice frame 10a DLCI registration table 10b transmission buffer 10c transmission frame monitoring unit 10d frame transmission control unit 10e LAN router unit 10f reception buffer 10g reception frame monitoring unit 10h frame reception control unit 11e communication Processing controller 20a 20b LAN frame received by frame relay router 20a ■ 20b ■ receiving LAN frames 20a ■ (20b ■) FR frame 50 encapsulates the 50 a to 50 d. Router 51a frame relay communication device 60a to 60e LAN 70a to 70h terminal 100 Frame Relay network 200 a local area network

Claims (8)

[Claims] 1. A frame relay router for relaying a priority frame and a non-priority frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner, wherein a frame relay frame (hereinafter, FR frame) is communicated. DLCI registration means for registering priority / non-priority, authorized information rate, guaranteed burst amount, and excess burst amount in accordance with a DLCI identifier for identifying a partner, and receiving a frame (hereinafter, a LAN frame) from the local area network. LAN frame receiving means for dividing into FR frames and storing the same in a transmission buffer; and transmitting traffic of a priority FR frame or a non-priority FR frame based on a DLCI identifier for identifying a communication partner held in the FR frame. Monitor sending According to the monitoring result of the frame monitoring means and the transmission frame monitoring means, the FR
Frame transmission control means for controlling frame transmission; and frame relay transmission means for transmitting the FR frame stored in the transmission buffer to the frame relay network under the control of the frame transmission control means. The control means determines whether the monitoring result of the transmission frame monitoring means has a priority F for a predetermined time.
If the R frame is not transmitted, the non-priority FR frame is transmitted at a throughput based on the registered committed information rate, the guaranteed burst amount, and the excess burst amount. If the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is transmitted. A priority FR frame is transmitted at a throughput based on the registered committed information rate, guaranteed burst amount, and excess burst amount, and a non-priority FR frame is registered in the priority frame from the link band of the physical link line of the frame relay interface. A frame relay router characterized by controlling a transmission rate so as to transmit in a band obtained by subtracting a throughput based on a guaranteed information rate, a guaranteed burst amount, and an excess burst amount. 2. A frame relay communication device for relaying priority data and non-priority data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner, wherein the frame relay communication device supports a DLCI identifier for identifying a communication partner of an FR frame. Priority / non-priority, certified information rate, guaranteed burst amount,
DLCI registration means for registering the amount of excess burst, communication data reception means for receiving data from a communication terminal, dividing the FR frame and storing the divided data in a transmission buffer, and identifying a communication partner held in the FR frame Transmission frame monitoring means for monitoring the transmission traffic of a priority FR frame or a non-priority FR frame based on the DLCI identifier to be transmitted.
Frame transmission control means for controlling frame transmission; and frame relay transmission means for transmitting the FR frame stored in the transmission buffer to a frame relay network under the control of the frame transmission control means. Means for monitoring the transmission frame by the transmission frame monitoring means;
If the R frame is not transmitted, the non-priority FR frame is transmitted at a throughput based on the registered committed information rate, the guaranteed burst amount, and the excess burst amount. If the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is transmitted. A priority FR frame is transmitted at a throughput based on the registered committed information rate, guaranteed burst amount, and excess burst amount, and a non-priority FR frame is registered in the priority frame from the link band of the physical link line of the frame relay interface. A frame relay communication device that controls a transmission rate so as to transmit data in a band obtained by subtracting a throughput based on a certified information rate, a guaranteed burst amount, and an excess burst amount. 3. A frame relay router for relaying a priority frame and a non-priority frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner. Frame length registering means for registering a first maximum frame length in a priority FR frame and a second maximum frame length in a non-priority FR frame; and receiving a LAN frame from the local area network, LAN frame receiving means for dividing and storing in a transmission buffer, and a transmission frame for monitoring the transmission of a priority FR frame or a non-priority FR frame based on a DLCI identifier for identifying a communication partner held in the FR frame. Monitoring means; And a frame relay transmitting means for transmitting the FR frame stored in the frame relay network to the frame relay network, wherein the LAN frame receiving means detects the priority FR frame within a predetermined time as a result of monitoring by the transmission frame monitoring means. If not transmitted, the above non-priority F
The R frame is divided within the second maximum frame length, and if the priority FR frame is transmitted within a predetermined time, the non-priority FR frame is transmitted within the first maximum frame length shorter than the second maximum frame length. A frame relay router, which is divided and stored in the transmission buffer. 4. A frame relay communication apparatus for relaying priority data and non-priority data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner, wherein the frame relay communication device supports a DLCI identifier for identifying a communication partner of an FR frame. Frame length registration means for registering a first maximum frame length in a priority FR frame and a second maximum frame length in a non-priority FR frame; and receiving data from the communication terminal and dividing the data into the FR frames. Communication data receiving means for storing in a transmission buffer; transmission frame monitoring means for monitoring whether a priority FR frame or a non-priority FR frame is transmitted based on a DLCI identifier for identifying a communication partner held in the FR frame. The FR frame stored in the transmission buffer is transferred to the frame relay. And a frame relay transmitting means for transmitting to the network. The communication data receiving means, if the priority FR frame is not transmitted within a predetermined time as a result of monitoring by the transmission frame monitoring means, transmits the non-priority FR frame. If the priority FR frame is transmitted within a predetermined time and the non-priority FR frame is transmitted within a predetermined time, the non-priority FR frame is divided into a first frame shorter than the second maximum frame length.
A frame relay communication device that divides the data into frames within the maximum frame length and stores the data in the transmission buffer. 5. A frame relay router for relaying a frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner, a LAN frame receiving means for receiving a LAN frame from the local area network, Dividing means for dividing the received LAN frame into FR frames; queuing means for associating the divided FR frames with each other in a transmission buffer; and transmitting the FR frames queued in the transmission buffer to the transmission buffer. And a discarding unit for discarding the FR frame associated with the FR frame when discarding the frame frame from the frame relay router. 6. A frame relay communication device for relaying data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner, a communication data receiving means for receiving communication data from the communication terminal, Dividing means for dividing the communication data into FR frames, queuing means for associating the divided FR frames with each other and queuing them in a transmission buffer, and transmitting the FR frames queued in the transmission buffer from the transmission buffer. A frame relay communication device, comprising: a discarding unit for discarding an FR frame associated with the FR frame when discarding the frame. 7. A frame relay router for relaying a frame from a local area network to a frame relay network based on a DLCI identifier for identifying a communication partner, a LAN frame receiving means for receiving a LAN frame from the local area network, A dividing means for dividing the received LAN frame into FR frames; a queuing means for setting a timer corresponding to the divided FR frame and queuing the transmission buffer; and a timer corresponding to the FR frame after being queued. And a discarding means for discarding the FR frame if a predetermined time has elapsed. 8. A frame relay communication device for relaying data from a communication terminal to a frame relay network based on a DLCI identifier for identifying a communication partner, a communication data receiving means for receiving communication data from the communication terminal, Dividing means for dividing the communication data into FR frames, queuing means for setting a timer corresponding to the divided FR frames, and queuing in the transmission buffer; and a timer corresponding to the FR frames after being queued. And a discarding means for discarding the FR frame when a predetermined time has elapsed.