JPS5970336A - Receiving buffer managing system - Google Patents

Abstract

PURPOSE:To return a signal allowing the transmission of a packet to a transmission terminal, by adding the number of buffers decided with a preset window size to the occupied bufer number after confirming the fact that the said result of addition does not exceed the registered buffer number. CONSTITUTION:A packet exchange sets a call between terminals 2B and 2A in the normal packet procedure. When the terminal 2A receiving a data packet returns a packet RR possible for transmission, a packet analysis circuit 41 analyzes the returned transmissionable packet RR and starts a buffer managing circuit 43. The buffer managing circuit 43 extracts an occupied buffer number (q), a window size ws, a transmission sequence number ps, and a receiving sequence number pr, and calculates the data packet number transmitted consecutively by the terminal 2B, adds the number(ps-pr+1)subtracting the said result of calculation from the window size ws to the occupied buffer number (q), and discriminates whether or not the said result of calculation exceeds the registered buffer number (m), and when the number does not exceeds, the transmissionable packet RR is transferred to a packet transmission circuit 42 and transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION (al) Technical Field of the Invention The present invention relates to a reception buffer management system, and particularly to a reception buffer management method in a packet switching network that allows reception packets to occupy a buffer for a terminal within a pre-registered number of reception packet buffers. Concerning buffer management methods.

Prior Art and Problems FIG. 1 is a diagram showing an example of a conventional reception buffer management system in this type of packet switching network, and FIG. 2 is a diagram showing an example of the packet transfer process in FIG. 1. 1st
In the figure, packet switching 1 constituting the packet switching network
al controls packet communications between the plurality of terminals 2 it accommodates. The packet exchange tJI 11 has a plurality of buffers 3 in which packets arriving at each terminal 2 are temporarily stored. Each terminal 2 registers the required number of buffers (hereinafter referred to as the number of registered buffers m) when joining the packet exchange tal.

The packet switch 1 manages the number of buffers 3 occupied by packets arriving at each terminal 2 (hereinafter referred to as the number of occupied buffers q) using a buffer management unit 4, and when the number of occupied buffers q exceeds the number of registered buffers m, If so, reception of the packet to the terminal 2 is refused. In Figure 2, in order for terminal 2 (B) to perform packet communication with terminal 2 (A), it sends a call request packet 7) to packet switch 1 to terminal 2 (A).
After transmitting R, packet switch l transmits an incoming call packet CN to terminal 2 (A). The incoming call packet 7) C'
If the terminal 2 (A) which received the N signal is able to communicate, it returns the incoming call acceptance (Pakeso) CA to the packet switch 1. Packet switch 1, which has received the call-receivable packet CA, sets up a call between both terminals 2(A) and 2(B), and terminal 2(B)
A connection completion packet CC is returned to the client. In the above process, terminals 2(A) and 2(B) determine the window size ws in the call, that is, terminal 2(B)
) sets the number of packets that can be continuously transmitted without waiting for a signal indicating a receivable state to be returned. In the call shown in FIG. 2, it is assumed that the window size ws is set to 3. Thereafter, the terminal 2 (B) sequentially transmits data packets DT (ps) to which transmission sequence numbers ps have been assigned.

Terminal 2 (A,), which has received the data packet DT (1) S = 2) with the transmission sequence number ps = 2, confirms that it is ready to receive the data packet) DT (ps = 3) and beyond. Sendable packet RR (p'r=3)
, terminal 2 (B) returns the data packet DT(p') based on the set window size ws=3.
s = 3) to DT (ps = 5). On the other hand, the packet switch 1 receives data packets DT sent from each terminal 2 including terminal 2 (B) to terminal 2 (A).
(ps) is stored in the buffer 3, the buffer management unit 4 monitors the number of occupied buffers q, and the terminal 2
When receiving the data packet DT (ps=4) transmitted in (B), if the number of occupied buffers q has already reached the number of registered buffers m, then the packet switch 1 determines that terminal 2 <B
) to the axle notification bucket) return the RNR to the data packet server)
The transmission of DT (ps) is temporarily stopped, and the received data packet DT (ps=4) is discarded.

As is clear from the above explanation, in a conventional reception buffer management circuit, although the terminal 2 (B) transmits the data packet DT based on the set window size W3, the number of occupied buffers q is equal to the number of registered buffers. The data packet 1-Dj (p's) sent to exceed m is discarded and must be retransmitted after the axle is resolved, and the packet exchange tal also discards the data packet DT and discards the axle notification packet R. , NR must be sent back, consuming processing power.

(C1 Purpose of the Invention The purpose of the present invention is to eliminate the shortcomings of the conventional reception buffer management system as described above and to realize a means for reducing invalid processing of packet switching equipment and terminals caused by reception buffer congestion. exist.

(d+ Structure of the Invention) The purpose of this invention is to enable a packet receiving terminal to send out a signal indicating that it is ready to receive packets in a packet switching network that allows a terminal to occupy a buffer for receiving packets within a pre-registered number of buffers for receiving packets. Adds the number of notifications determined by the preset window size to the number of occupied buffers, and after confirming that the addition result does not exceed the number of registered buffers, sends back a signal to the packet sending terminal to allow packet transmission. This is achieved by providing a means to do so.

tel　Embodiments of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram showing a reception buffer management method according to an embodiment of the present invention, and FIG. 4 is a diagram showing an example of the packet transfer process in FIG. 3. Note that the same reference numerals indicate the same objects throughout the figures. In FIG. 3, various packets transmitted by packet receiving terminals (in this example, terminals 2, (A, , In the example, it is sent back to terminal 2 (13). In Figure 4,
Terminal 2 (B) sends a call request packet CR to terminal 2 (A) to packet switch 1 in the same way as in FIG. When the terminal 2 (A) returns the incoming call acceptance packet CA, the packet analysis circuit 41 in the buffer management unit 40 analyzes the returned incoming call acceptance packet CA, activates the buffer management circuit 43, and returns the incoming call acceptance packet. Communicate that the activation is by CA. The buffer management circuit 43 extracts the number of occupied buffers q held by the packet switch 1 corresponding to the terminal 2 (A) and the window size ws extracted and held from the incoming call acceptance packet CA, adds them together, and calculates the corresponding number of buffers q. After confirming that the addition result does not exceed the number m of registered buffers registered by the terminal 2 (A), the addition result is returned to the bucket exchanger 1 to update the number q of occupied buffers, and then
The packet sending circuit 42 is caused to send out the incoming call acceptance packet 1-CA. The packet switch 1 connects the terminal 2 (A
) and 2 (B), a call is established and the connection is completed (Paqueso)
The CC is sent back to terminal 2 (B). Thereafter, the packet switch 1 transmits the data packet switch 1-DT transmitted by the terminal 2 (B).
Each time (pS) is transmitted to terminal 2 (A), 1 is subtracted from the number of occupied buffers q held. Data packet DT (
Terminal 2 (A) that received the packet (A) can send the packet RR
When (pr) is returned, the packet analysis circuit 41 analyzes the returned sendable packet)RR(pr), activates the buffer management circuit 43, identifies the call, and identifies the sendable packet)RR(pr).
pr). The buffer management circuit 43 determines the number of occupied buffers q and the window size WS that the bucket exchanger 1 holds corresponding to the terminal 2 (A).
, the transmission sequence number ps extracted and held from the latest data packet DT (ps) transmitted from the terminal 2 (B) regarding the call, and the latest ready-to-send packet RR ( The reception sequence number pr to be extracted and held from the terminal 2
Number of data packets continuously transmitted by (B) pr+w
After calculating s-ps-1, the calculation result is subtracted from the wind size ws, which is the number W, S-pr-ws+ps+1=p
s-pr+l is added to the number of occupied buffers q, and it is determined whether the addition result exceeds the number m of registered buffers.

If the addition result does not exceed the number m of registered buffers, the number q of occupied buffers held by the bucket exchanger 1 is updated based on the addition result, and the packet analysis circuit 41 updates the received sendable bucket) RR(pr). Packet sending circuit 4
Transfer it to 2 and send it out.

The bucket exchanger 1 is capable of transmitting packets (Pakeso) R as in Fig. 2.
R(pr) is sent to terminal 2 (B). If the addition result exceeds the number m of registered buffers, the packet sending circuit 42 does not send out the sendable packet RR (pr), and the time point indicated by the timing circuit 44 is registered as the timing □ circuit 45 ← corresponds to the call. and register it. Thereafter, when a preset time has elapsed, the selection circuit 46 activates the buffer management circuit 43 again and notifies it that the activation is based on the call identification and sendable bucket (RR(pr)).

The buffer management circuit 43 determines whether or not the sendable packet data (RR(I)r) can be returned in the same process as described above. Furthermore, the communication ends, and the terminal 2 (B) sends the recovery request bucket)CQ to the bucket exchanger 1, and the recovery request bucket 1-CQ is sent to the bucket exchanger 1.
The bucket switch 1 that received the disconnection instruction packet CI transmits the disconnection instruction packet CI to the terminal 2 (A), and when the terminal 2 (A) that received the disconnection instruction packet CI returns the disconnection confirmation bucket CF, the packet analysis circuit 41 sends the disconnection instruction packet CI to the terminal 2 (A). Confirmation packet I-CF
The buffer management circuit 43 is analyzed, and the buffer management circuit 43 is notified that the activation is based on the call identification and disconnection confirmation packet CF. The buffer management circuit 43 performs packet switching ta 1
Extracts the window size Ws, the transmission sequence number ps, the reception sequence number pr, and the number of occupied buffers q corresponding to the terminal 2 (A) held by the terminal 2(A),
Thereafter, the terminal 2 (B) calculates the number of data packets pr+ws-ps-1 to be continuously transmitted, and after subtracting the calculation result from the number of occupied buffers q to update the number of occupied buffers q, the packet sending circuit 42 packet analysis circuit 41
The received disconnection confirmation bucket CF is sent out. The packet exchange tJI11 returns the recovery completion packet y) CF to the terminal 2 (B).

As is clear from the above description, according to the present embodiment, the bucket switch 1 controls the terminal 2 (B
) continuously transmits the number of data packets DT (ps) allowed by the window size ws, the terminal 2
In order to allow packet communication after confirming by the buffer management unit 40 that the number of occupied buffers q for (A) does not exceed the number m of registered buffers, the terminal 2 (B) uses an invalid 0 data packet (ps) DT (ps). The transmission is prevented, and as a result, the packet exchange tJI11 is also prevented from performing invalidation processing such as sending out the axle notification packet RNR.

In this embodiment, the number of occupied buffers q is held for each terminal, but it may be held for each outgoing packet, incoming packet, or relay packet in the packet switch 1 for wheel management, etc. Although many modifications may be considered, the effects of the present invention remain the same in any case. Further, FIGS. 3 and 4 are also only one embodiment of the present invention, and for example, the configuration of the buffer management unit 40 is not limited to that shown in the figures, and many other modifications may be considered. However, the effects of the present invention remain the same in either case. Furthermore, the configuration of the packet switching network that is the object of the present invention is not limited to that shown in the drawings, and many variations can be considered in the configuration of a plurality of packet switching devices 1. However, the effect of the present invention remains unchanged.

ff) Effect 1 of the invention As described above, according to the present invention, in the packet switching network,
Invalid processing of the packet switching equipment and terminals caused by the shaft of the receiving sofa is reduced, and the efficiency of the packet switching network is improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional reception buffer management method, FIG. 2 is a diagram showing an example of the packet transfer process in FIG. 1, and FIG. 3 is a diagram showing an example of a reception buffer management method according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of the packet transfer process in FIG. 3. In the figure, 1 is a packet switch, 2 is a terminal, 3 is a filter, 4 and 40 are buffer management units, 41 is a packet analysis circuit, 42 is a packet sending circuit, 43 is a buffer management circuit, 44 is a timing circuit, and 45 is a timing circuit. Registration circuit, 46 is selection circuit, CR is call request packet, CN
is an incoming packet, CA is an incoming packet, CC is a communicable bucket, DT is a data packet, RR is a sendable packet, RNR is an axle notification packet, CQ is a recovery request 2 packet, CI is a disconnection instruction packet, and CF is a disconnection packet. In the confirmation packet, ps is a transmission sequence number, pr is a reception sequence number, ws is a window size, q is the number of occupied buffers, and m is the number of registered buffers. 3 1st Figure 2(B) /
'2(A) Kaya 2721

Claims (1)

[Claims] In a packet switching network that allows a terminal to occupy a buffer for receiving packets within the pre-registered number of buffers for receiving packets, a preset window size is used when a packet receiving terminal sends a signal indicating that it is ready to receive packets. The method is characterized by providing means for adding a determined number of buffers to the number of occupied buffers and, after confirming that the addition result does not exceed the number of registered buffers, returning a signal permitting packet transmission to the packet transmitting terminal. Receive buffer management method.