JPH03262233A - Packet exchanging system in isdn packet exchange system - Google Patents

Abstract

PURPOSE:To improve the packet transfer capability by using a packet processor to implement protocol processing of a packet and implementing the packet transfer between a terminal accommodation equipment and the packet processor via a packet highway controller and a packet switch or the like. CONSTITUTION:Packet processing such as a B-channel or the like is implemented by a packet processor 12 controlled by the time division switch 11 of a line exchanging section. Then B-channel packet transfer is implemented by a packet switch 15 and a packet highway 14 via a packet highway controller 16 connected directly to a terminal accommodation equipment 18 and the unit 12. An incoming number translation and path selection to a packet call are similarly processed in a lump by the exchange controller 20 in the case of the line exchange. The processing is similar to a D channel, the packet transfer capability is improved more than the case of multiplex transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to switching systems for communication networks, in particular to ISDN switching systems.

(Prior art) Conventionally, ISDN (Integra
tedServices Digital Netwo
rk・Digital Comprehensive Communication Network) function when adding
There is a configuration in which packet switching processing is performed in a circuit switching device and another device, and the devices are connected by a line.

Figure 2 shows an example of the configuration of a conventional ISDN switching system.
1 is a time division switch that performs circuit switching (
TSW), 2 is a terminal accommodation device (5LIC) that accommodates terminals through the I interface, and 3 is a time division multiplex highway (HW) that connects the 5LIC and TSW by time division multiplexing.
), 4 is a terminal by I interface (TML), 5
is a control bus (S,
-BUS), 6 is a switching control processing device bus (SCM-BUS) that connects the switching control processing device and other devices, 7 is a switching control processing device (SCM) that controls switching processing based on call control signals, 8 9 is an inter-device line (ML) that connects the packet switching device and the line switching system, 9 is the 9 packet switching device (PSM) that performs packet switching processing, and 10 is the line that exchanges packet information between the circuit switching system and the PSM. This is a packet multiplexing device (PMM) that multiplexes and transmits data.

Figure 3 shows an example of a connection sequence for 4 packets of the B channel using the conventional method.
(Setting request) When the message is received by 5LIC2-1, 5LIC2-1 sends 5-BUS s and S to SCM 7.
A call setup request is made via CM-BUS 6, and the SCM
In response to this, 5LIC,? 5IJC2-2 sends back a call setup acceptance confirmation to terminal 4-1, and 5IJC2-2 receives this and
CALL PROC (call setting processing in progress) is returned to 1.

After returning the call setup acceptance confirmation, the SCM 7 confirms the caller and sends a call setup request to the PSM 9 via the PMM 10 and ML8. If PSM 9 is able to accept the packet call, it returns a call setup confirmation to 80M7 via ML8 and PMM 1o, and in response to this, SCM 7 sends TSW
Connect the wire between 5LIC2-1 and PΔIMZ0 to IJ-, send a call connection instruction to 5LIC2-1, and
IC2-1 sends C0NN (called party response) to terminal 4-1, terminal 4-1 confirms this and sends C0NN ACK (
When the 5LIC 2-1 returns a call connection confirmation (C0NN reception confirmation) to the SCM 7, the 5LIC 2-1 sends a call connection confirmation to the SCM 7, and is ready to accept a packet call. The CR (call request) packet from terminal 4-1 is T.
IE packet multiplexing is performed in pmlo via SWl, PSM 9 performs Z packet protocol processing, called party number translation, and route selection via ML8, and sends PMM 10 to SCM 7 while retaining ('R)e ket. Notify of incoming call via. In response to this, the SCM 7 again performs callee number interpretation and strategy selection in order to determine the outgoing route as a circuit switching system, and sends a call setup request to the outgoing 5LIC 2-2.
5LIC2-2 receives this and sends SETUP to terminal 4.
-2.

Terminal 4-2 receives this and determines the response channel.
Send 0NN. 5LIC2-2 receives this and sends a call setup confirmation back to SCM 7, and when SCM 7 receives this, it sends a response to the incoming call notification to PSM 9, waits for confirmation from PSM 9, and sends the PMM on TSWl.
10 and 5LIC2-2, sends a call connection confirmation, and sends C0NN ACK to terminal 4-2.

The SCM 7 requests the PSM 9 to set up the outgoing i4kesoto call, and the PSM 9 makes preparations for accepting the packet call, returns the call setup confirmation to the SCM 7, and sends a call setup request to the PSM 9.
In response to this, M7 sends an acknowledgment to the ingress side of PSM 9. In response to this, PSM 9 edits the held CR/e questo into a CN (incoming call notification) packet, and sends it to PMM 10, TSWl, 5LIC2-
2 to the terminal 4-2. Next, the CA (incoming call response) and 9 messages returned by the terminal 4-2 are the already set numbers, that is, 5 LIC 2-2, TSW 1, PMM.
Accepted via PSM 9 via LO, CC (Call Acceptance) No! Edit to PIV! M 10, TSW 1.5
The data is returned to the terminal 4-1 via the LIC 2-1, the packet call connection is completed, and the packet data can then be transferred.

FIG. 4 is an example of a D channel packet connection sequence according to the conventional method. First, when the SABME frame is accepted by the 5LIC 2-1 from the terminal 4-1, the 5LTC 2-1 requests the SCM 7 to set up a data link, and the SCM 7
If this is accepted, a data link setting confirmation is sent back to 5LIC2-1, and 5LIC2-1 receives this and sends a UA back to terminal 4-1 to establish a data link.
If the PSM preparation is not completed, an RNR frame is sent to the terminal 7-1, and the transmission of the e-kerat is temporarily stopped.

When SCM 7 accepts a data link setup request, P
A call setup request for a packet call is made to PSM 9 via MMJO and ML8, and if PSM 9 can accept the packet call, it returns a call setup confirmation to SCM 7. Upon receiving this, SCM 7 sends a call setup request to PSM 9 on TSW Z. PMM 10 and 5LI
The communication signal between C2-1 is connected, a call connection instruction is given to 5LIC2-2, an RR frame is transmitted from 5LIC2-1, and preparations for accepting a packet call are completed. The subsequent procedure is the same as in the case of B channel/Gukerat.

(5) (6) (Problems to be Solved by the Invention) However, as described above, when adding ISDN functionality to a conventional circuit switching system, packet switching processing is performed in a separate device from the circuit switching processing device. In the method of connecting the devices with a line, (1) No'kerato's transfer capacity is limited by the processing capacity of the packet multiplexing device, and the line speed and number of lines between the packet switching device and the circuit switching processing device.

(2) The connection time of a packet call is still determined by the time from call setup to call connection in the circuit switching equipment, the time for called number control translation, strategy selection, and the time for call setup, call number control translation, and route in the packet switching equipment. Since the selection time and the communication time for exchanging call control signals between the packet switching device and the circuit switching device are added, the connection delay time increases, and processing capacity is reduced when performing e-ket exchange. restrictions will be added.

As described above, the present invention provides an ISDN in a circuit switching system.
It is an object of the present invention to provide an ISDN switching system that solves the limitations on switching performance, such as the limitations on packet transfer capability when adding functions and the increase in delay in connection time of packet calls.

(Means for Solving the Problems) The present invention provides an ISDN switching system in which an ISDN function is added to a circuit switching system.
A network interface (hereinafter abbreviated as ■interface) provides a terminal device that accommodates terminals, a packet processing device that performs packet protocol processing, a time division switch that switches between each device using a circuit switching method, and a A packet switch that performs switching using a 74-ket exchange method is provided, and a packet no-iway control device that controls packet no-iway between the Norkerato switch and the terminal accommodating device is directly connected to the end-unaccommodated device, and the terminal-unaccommodated device and Packet transfer between packet processing devices is performed by a packet switch via a packet gateway control device,
In addition, it has a switching control device that processes call control signals from each device and determines the connection route of the call, and this switching control device processes calls such as packet and circuit switching call translation, strategy selection, etc. Performs connection route determination processing all at once,
In addition, by providing a control bus directly connected to the exchange control device and arranging the packet processing device and the end-unaccommodated device under the control bus, the communication between the processing device, the end-unaccommodated device, and the exchange control device is Call control signals are exchanged via a control bus.

(Embodiment/Operation) FIG. 1 is a block diagram showing an embodiment of the present invention.
is a time division switch (T
SW), 12 is a packet processing device (PHM) that performs packet protocol processing, 13 is a time division multiplexing device (HW) that connects the PHM and edge-unaccommodated devices and TSW by time division multiplexing, and 14 is a kerato switch and P
15 is the packet switch (PSW) that connects the HM and the Pakenotono Iway control device, 15 is the packet switch (PSW) that transfers the information between the IM and the end unaccommodated device (5LIC), and 16 is the packet switch from the 5LIC (9) 17 is a terminal (TML) using the I interface; 18 is a terminal using the ■ interface; An end-unaccommodated device that accommodates a terminal (
5LIC), 19 is a switching control processing device bus (SCM-BUS) that connects the switching control processing device and other devices, and 20 is a switching control processing device (SCM-BUS) that performs switching control based on call control signals.
CM), 2 is a control bus (5-BUS) that transmits call control signals from the SLIC and PHM.

FIG. 5 is an example of a connection sequence of B channel packets according to the present invention. First, when a 5ETTJP message is received from the terminal 17-1 on 5LIC1B-1, 5LIC1
8-1 connects SCM 10 to 5-BUS 21 and SCM-
A call setup request is made via BUS 19, and SCM 20
When this is accepted, a call setup acceptance confirmation is returned to the 5LIC 18-1, and the 5LIC 1B-1 receives this and returns a CALLPROC to the terminal 17-1. SCM 20
Then, after returning the call setup acceptance confirmation, confirm the caller, select an available ingress PHM 72 in the system, and select the ingress PHM 72 that can be used in the system.
A call setup request is made to HM 12, and if PHM 12 can accept the 4K call, it returns a call setup confirmation to SCM 20. Upon receiving this, SCM 20 sends 5LIC1B-1 and PT (MJ2) on TSW l. (10) Connect the space between 5LIC2B-1 and give call connection instructions.
and send C0NN from 5LIC1B-1 to terminal 17.
-1, terminal 17-1 confirms this and sends it to C0NN A.
When the CK is returned, the 5LIC1B-1 sends a call connection confirmation to the SCM2O, and is ready to accept a packet call. The CR (call request) packet from terminal 17-1 is TSW 1
1 through PHM 22, PHM
12 notifies the SCM 20 of the incoming call while holding the CR/f packet.

SCM? Upon receiving this, 5LIC 1B-2 translates the called number, selects a route, and issues a call setup request to 5LIC 18, -2 on the outgoing side, and 5LIC 1B-2 receives this and transmits SETUP to terminal 17-2. Terminal 17-2 receives this, determines the response channel, and transmits CONN. 5L
When IC1B-2 receives C0NN, it confirms the call setup with S.
Send to CM 20. When SCM2O receives this, it selects the output PHM 12 that can process the response channel (this example shows the case of the same PHM as the number of people), TS
Connect the nozzle between 5LIC1B-2 and PHM 12 on WI, send a call connection confirmation to 5LIC18-2,
5LIC1B-2 receives this and sends C to terminal 17-2.
Send 0NN ACK.

The SCM 2O then requests the outgoing PHM 12 to set up the call, the PHM 12 prepares to accept the packet call, and sends the call setup confirmation back to the SCM 20. Upon receiving this, the SCM 2O sends a request to the incoming PHM 12. Send acknowledgment. Incoming PI (C that was held in response to this in M 12)
R) Send the CR packet to the egress PHM 12 via PSWI 5, and the egress PHM J 2 sends this CR packet to the CN
(Incoming call notification) Edit into packet, TSW 11.5LI
It is transmitted to terminal 17-2 via CJ 8-2. next,
The CA (call response) packet returned by the terminal 17-2 is sent to the node that has already been set, that is, 5LIC1B-2.
, through TSW 11, the receiver is attached to the output side P decoy 12, and the PS
Input side PHM 1 via WI5 to input side PHM 12
In 2, edit to CC (call reception)/queket and TSWll,
The data is returned to the terminal 17-1 via 5LIC1B-1, the packet call connection is completed, and the A' packet data can then be transferred.

FIG. 6 is an example of a connection sequence for nine D channels according to the present invention. First, when terminal 17-1 receives a SABME frame on 5LIC1B-1, SL controller C18
-1 is SCM20 K 5-BUS 2 J and SCM
- Make a data link setting request via BUS 19,
SCM2O accepts this and returns data link setting confirmation to 5LIC1B-1, and 5LICZ 8-1 receives this and returns UA to terminal 17-1 to establish a data link, but PHM 12 prepares Since this has not been completed, an RNR frame is sent to the terminal 17-1, and the transmission of e-kets is temporarily stopped. After returning the data link setup confirmation, SCM 2 o selects the ingress PHM 12, issues a call setup request to the ingress PHM 12, and
2 is SCM if it is possible to accept a knock-quet call, l!
SCM2O sends a call setup confirmation back to 5LIC18-1, and in response to this, SCM2O issues a call connection instruction to 5LIC18-1, and 5LIC2B
-2, the RR frame is transmitted and preparations for accepting a packet call are completed. The 0CR (call request) packet from the terminal 17-1 is treated as a simple processing (information) frame by the 5LIC 18-1 and transferred to the ingress PHM 12 by the PSW 15 via the PHC 16-1, and the packet protocol is processed by the ingress PHM J2. Then, while holding the CRte key, the SCM2O is notified of the incoming call. SCM 20 receives this (13), translates the called party number, selects a strategy, and sends the egress 5LIC1B-
5LIC1B-, 2 sends a call setup request to terminal 17-2, and 5LIC1B-, 2 receives this and transmits 5ETUP to terminal 17-2. Terminal 17
-2, the reception determines the response channel and transmits W Zen-step H Meter-turn-H C0NN. When 5LIC1B-2 receives C0NN, it sends a call setup confirmation to SCM 20. When SCM2O receives this, it selects the output side PHM 12 that can process the response channel (this example shows the case of the same PHM as the crowd), 5LIC1B-2
5LIC1B-2 sends a call connection confirmation to terminal 1.
7-2. SCM,l!
Next, in the same way as in the case of the B channel, the CR packet held from the incoming PHM 12 is sent to the PHM 12 through the procedures of call setup request, call setup confirmation, and acknowledgment.
SWI 5 to egress PHM 12, egress PH
M12 edits this CR packet into a CN e-ket and sends it to 5LIC via PSWI5 and PHCf6-2.
1B-2, and transmits it to the terminal 17-2 as a frame (3). Next, the C A Rket returned by the terminal 17-2 reversely follows the same route as the CRS CN packet and is transmitted to the terminal 17-1 as a CC(14) packet, completing the connection of the packet call.

(Effects of the Invention) As described above, according to the present invention, (1) Protocol processing of packets is performed by the packet processing device, and mother kerat transfer between the terminal-unaccommodated device that accommodates the terminal and the packet processing device is performed by the packet processing device. By using a packet switch via a packet highway control device that is directly connected to the unaccommodated device, the packet transfer rate is higher than when packets are transferred via a packet multiplexer and an inter-device line (usually up to 64 kbps) as in the past. Transfer ability can be expected.

(2) In addition, the called party number translation and route selection for calls are performed all at once by a switching control device similar to circuit switching, and the packet processing device is installed under a control bus that is directly connected to the switching control device. By doing so, call control signals are exchanged between the packet processing device and the exchange control device via the control bus, so call control signals are exchanged on the line between the devices via the e-kerato multiplex device as in the past. or exchange control device and i
It is possible to reduce redundant processing such as calling party number translation and route selection on both devices of the e-ticket exchange device, reducing connection delay time for calls, and solving processing capacity limitations in ISDN packet exchange. can be solved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a conventional ISDN switching system, Fig. 3 is an explanatory diagram of a conventional packet connection sequence, and Fig. 4 is a conventional packet connection sequence. FIG. 5 is an explanatory diagram of the present invention. Fig. 6 is an explanatory diagram of a /4'ket connection sequence according to the present invention. 1.11...Time division switch, 12.../4'kenoto processing device, 3,13...Time division multiplexing...Iway,
14...Packet Highway, 15...Packet Switch, 16...Packet Highway Control Device, 17
0.・Terminal, 18... End unaccommodated device, 19... Exchange control processing device/JS, 20... Exchange control processing device, 2
1...Control/Gus. Electric! l! ! ! '< , N Soguri■■■〇- -P+---PP+--('J ('J, -IN (
“lg10to ■O 298

Claims (1)

[Scope of Claims] An ISDN switching system in which an ISDN packet switching function is added to a line switching system, comprising: a terminal accommodation device that accommodates a terminal using an ISDN user/network interface; a packet processing device that performs packet protocol processing; Terminal housing includes a time division switch that switches between each device using a circuit switching method, a packet switch that switches between each device using a packet switching method, and a packet highway control device that controls the packet highway between the packet switch and the terminal accommodation device. a switching control device that is directly connected to the device, processes call control signals from each device, and collectively determines connection routes for packets and circuit-switched calls; A packet switching method in an ISDN switching system, which is installed under a control bus directly connected to a switching control device, and is characterized in that call control signals are exchanged between each device via the control bus.