JP3333145B2 - Protocol inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention newly develops an upper layer protocol which is assumed to be used on a network having an explicit congestion notification, an explicit transmittable rate notification or a transmittable data amount notification function for a transmitting terminal. The present invention relates to a protocol inspection method used when checking the consistency with an existing protocol.

[0002]

2. Description of the Related Art When an upper layer protocol is developed based on a communication protocol stack that is hierarchized by function and divided into layers as in the OSI 7-layer model, control performed across layers as a communication protocol is performed by an upper layer. It is performed after both the implementation of the lower layer and the lower layer are completed, or is performed by computer simulation or the like.

[0003]

In the above prior art, a performance test or the like as a communication protocol can be tested not in simulation but in an actual environment until the entire protocol stack actually used is prepared. In recent years, various new transmission media have appeared and new lower-layer protocols using them have been specified one after another. However, since these lower-layer protocols are very complicated in terms of implementation, it is not long after the specifications are established. Devices that implement these lower layer protocols are not commercialized, and even if commercialized, the initial implementation has very limited functions and malfunctions.

[0004] For this reason, even if an attempt is made to mount an upper layer protocol utilizing these functions on these lower layer protocols, the actual operation cannot be performed unless the lower layer protocol operates normally. In addition, it takes time to wait for the implementation of a lower-layer protocol that operates normally, and it is assumed that the upper-layer protocol and the lower-layer protocol themselves do not see the light of the day in rapid progress.

The present invention has been made in view of such circumstances, and a lower layer protocol having an explicit congestion notification, an explicit transmittable rate notification, or a transmittable data amount notification function for a communication terminal is completely provided. It is an object of the present invention to provide a protocol inspection method capable of verifying the operation of an upper layer protocol using the function of a lower layer protocol at a stage before implementation.

[0006]

According to the present invention, a network mainly has an explicit congestion notification function or an explicit transmittable data amount notification function, and a network interface card (NIC) holds transmittable rate information. In order to realize the condition of the lower layer protocol, a test of the upper layer protocol is performed by simulating only the information necessary for the upper layer protocol.

In the prior art, the function that was made possible only by completing the protocol stack at the transmitting terminal is replaced with the explicit transmission available rate information among the lower layer protocol functions required by the upper layer protocol. A protocol stack is formed by realizing only a notification function and using a conventional function for data transmission / reception itself. That is, in order to achieve the above object, an invention according to claim 1 is a terminal connected to a network having an explicit congestion notification, an explicit transmittable rate notification, or a transmittable data amount notification function for a transmitting terminal. The upper layer located on the lower layer protocol when the output rate that can be transmitted by the lower layer protocol part located lower is dynamically changed using a communication protocol layered by function in the device and layered. A protocol inspection method for inspecting an operation characteristic of a protocol, wherein instead of actually operating a lower layer protocol, an output rate at which a lower layer protocol can be transmitted is simulated, and the generated output rate is notified to an upper layer. This allows the upper layer protocol to be implemented without actually implementing the lower layer protocol. And performing experience.

According to a second aspect of the present invention, in the protocol inspection method according to the first aspect, the generation of the transmittable output rate is performed by simulating the output rate at which the transmittable output rate is simulated. The present invention is characterized in that it is realized by reading in a table a set of a rate value of a lower layer that can be transmitted in advance and a number of packets that can be transmitted at the rate value as a unit.

According to a third aspect of the present invention, in the protocol inspection method according to the first aspect, when the output rate that can be transmitted is simulated, generation of the output rate is performed by transmitting a packet of an upper layer. This is realized by reading a set of a lower layer rate value that can be transmitted in advance as a unit and a transmittable time that can be transmitted at that rate value as a table, and switching the transmittable rate information when the transmittable time is reached. It is characterized by the following.

According to a fourth aspect of the present invention, in the protocol inspection method of the first aspect, when the transmittable output rate is simulated, the output rate is transmitted using a random number. A possible rate value is generated, and the duration of the transmittable rate value is also determined using a random number.

According to a fifth aspect of the present invention, there is provided the protocol inspection method according to any one of the first to third aspects,
It is possible to transmit by setting the number of packets or the transmittable time of the transmission rate to be read when generating the transmittable output rate in a simulated manner to a specific numerical value that is not used for displaying the normal packet number or the transmittable time. It is characterized in that the function of notifying by changing the rate value dynamically is stopped.

According to the first to fifth aspects of the present invention, instead of actually operating the lower layer protocol, a transmittable output rate of the lower layer protocol is simulated, and the generated output rate is converted to the upper layer protocol. The upper layer protocol test is performed without actually implementing the lower layer protocol by notifying the upper layer protocol, so that the test of the upper layer protocol can be performed without waiting for the complete implementation of the lower layer protocol. It is possible to improve the completeness of the protocol.

It is also possible to judge a function to be provided in the lower layer protocol and a required condition from the upper layer protocol side for its accuracy.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. The communication network to which the program inspection method according to the present embodiment is applied is an ATM between communication terminals.
(AsyncronousTransfer Mode). In this case, ABR, which is one of the service categories of the ATM service, is used as the lower layer protocol.
(Available Bit Rate) A case in which the service category is assumed to be used as a lower layer protocol will be described.

The communication terminal according to the embodiment of the present invention means, for example, a terminal device such as a computer that can use the ATM protocol, a network device terminating the ATM layer such as a router, and the like.

FIG. 1 shows an example of a basic configuration of a communication network to which the present invention is applied. As shown in FIG. 1, at least two opposing communication terminals 10 capable of operating an ATM protocol.
-1, 10-2 are connected to the ATM communication network 12.
Here, the ATM communication network 12 may include a network device such as an ATM switch 14. In the following, a communication terminal using such an ATM communication network 12 will be described in particular as an ATM.
An embodiment of the present invention will be described with respect to functions of a cell transmitting side.

FIG. 2 shows a functional model in the transmitting terminal. As shown in FIG. 2, an upper layer protocol (IP (Internet Protocol) or the like) is provided above the ATM layer 30.
Function 20 exists. The processing of the ATM layer 30 is mainly implemented by hardware to perform processing of actually transferring cells including the physical layer.
There are a C (Network Interface Card) 36 and the like, and a parameter setting function 32 and a rate control function 34 for performing a series of controls for performing transmission at a higher level.

In an ATM transmission terminal that transmits an ATM cell, in communication using ATM, connection setting is one of the above-mentioned control functions prior to data transfer, as a connection setting function (hereinafter referred to as a C plane function). 32). ATM connection setting is performed through parameter negotiation by signaling (hereinafter referred to as SVC (Switched Virtu
al Channel)) and a case where various parameters are manually input to software at the start of service to establish a connection (hereinafter, PVC (Permanent Virtual Channel)). In any case, the parameter values that determine the attributes of various connections and services by this C-plane function are VC (Virtual Channel) or VP (Virtual Pat.
By setting individually for each h), communication by ATM becomes possible.

Next, communication in the ABR service category will be described. In the communication by the ATM using the ABR service category, the RM (Retransmission) is performed during the communication in addition to the setting of various attributes at the time of the connection setting described above.
source management) cell, which is distinguished from other types of cells by the value of the PTI field in the header of the cell.
A communication element that can be accepted by a network element such as a switch in the M network or the receiving terminal is notified to the transmitting terminal as a transmission rate (ER: Explicit Rate) value.

When the ABR protocol is correctly implemented, a dynamic rate control function for the transmission rate value is realized. On the transmitting terminal side where the dynamic control function relating to the transmission rate value is realized, the rate value (ACR: All) calculated based on the ER value notified by the RM cell
ATM cells can be transmitted into the network at a rate according to the owed cell rate. For a detailed calculation method of the specified rate value, refer to the literature (TheATM Forum, Traffic Management Sp.
ecification 4.0, af-tm-056.000, April, 1996.). The transmitting terminal uses this rate information (ACR value)
Is stored in the memory. If necessary, the upper layer protocol function unit 20 transmits the A
The CR value can be used.

Also, the upper layer protocol function unit can access the stored transmission rate value and reduce the rate value to add a restriction. These functions are shown in FIG.
Upper layer protocol function 20 and ATM NIC3
6 is performed by a rate control function (hereinafter, referred to as a U-plane function) 34 located at an intermediate position between the rate control function 6 and the rate control function 6. The upper layer protocol function 20 can access the ACR value and use the information.

In the embodiment of the present invention, when a dynamic control function relating to the above-mentioned transmission rate value during communication is not realized in the transmitting terminal, that is, without having a rate control function,
NIC with only data transfer function (Network Interface
e Card) and a method of testing an upper layer protocol when only a device driver exists.

This corresponds to the case where the U plane function 34 does not exist in FIG. In this case, the implementation and operation of the upper layer protocol using the rate control function realized as the above-described protocol for the ABR service category of the ATM layer could not be studied conventionally.

In the protocol inspection method according to the first embodiment of the present invention, instead of actually operating the lower layer protocol, an output rate at which the lower layer protocol can be transmitted is simulated, and the generated output rate is generated. Notifying the upper layer protocol function unit by actually testing the upper layer protocol without actually implementing the lower layer protocol, and also simulating the transmittable output rate of the lower layer protocol, The generation of the output rate is realized by reading, as a table, a set of a lower layer rate value that can be transmitted in advance in units of an upper layer packet and the number of packets that can be transmitted at the rate value. In other words, the protocol inspection method according to the first embodiment of the present invention performs the test of the upper layer protocol using the rate control function of the ATM layer during communication by checking the rate control function for such an ABR service category. This is realized by using a function of simulating lower layer transmittable rate information for a transmission terminal that has not been realized.

FIG. 3 shows a functional configuration of a transmitting terminal to which the present invention is applied. 3, the transmitting terminal includes an upper layer protocol function unit 20, a data transmission function unit 40,
It comprises a lower layer transmittable rate information simulation function section 50 including a portion corresponding to the rate control function of FIG. From the upper layer protocol function unit 20, in addition to transmitting normal data to the lower layer transmittable rate information simulation function unit 50, which is a function block related to the rate control function, rate control information for transmitting data is acquired. Access is performed. To perform data transmission, the upper layer protocol function unit 20 writes data to a lower layer transmission buffer function provided in the data transmission function unit 40.

In order to obtain transmission rate control information, transmission rate value information is notified from the rate control function unit in the lower layer transmittable rate information simulation function unit 50 and a request from the upper layer protocol function unit 20 is received. In some cases, transmission available rate information is specified.

In the first embodiment of the present invention, in order to realize access from the upper layer protocol to the above-mentioned U-plane function, a NIC for an existing ATM layer protocol which does not implement an ABR service category protocol is used. The functions to be incorporated in the device driver will be described below.

FIG. 4 shows a configuration between devices relating to the ATM layer control in the transmitting terminal. As shown in the drawing, the lower layer transmittable rate information simulation function unit 50 includes a rate holding memory device 52, a rate / packet table memory device 54, a packet number counter device 56, a control device 5
And 8. Further, the data transmission device 40 'corresponds to the data transmission function unit 40 of FIG.

As described above, the rate holding memory device 52 is newly added to the lower layer transmittable rate information simulation function section 50 as a rate control section mainly in the device driver. Hereinafter, the value stored in the rate holding memory device 52 is referred to as an ACR value. Further, a memory device 54 for a rate packet table, which is a memory device different from the memory device 52, is prepared for each VC in the device driver. The number of packets that can be transmitted according to the possible rate value is described as a table. The number of combinations of the transmittable rate value and the number of packets that may be transmitted according to the transmittable rate value is arbitrary,
The controller 58 reads the above table (hereinafter, referred to as a rate packet table) composed of this combination cyclically in descending or ascending order, or randomly selects and reads out by generating random numbers. rate·
Even if the number of entries in the packet table is finite, it is possible to select entries indefinitely. FIG. 5 shows a specific example of the contents of the rate packet table.

The above two types of memory devices 52 and 54 and software having the processing contents shown in FIG.
8 implements the lower layer transmittable information generation simulation function described in claims 1 and 2. FIG. 6 shows the contents of processing related to the rate control function of the transmitting terminal in the protocol inspection method according to the first embodiment of the present invention.

In FIG. 6, when a connection with a communication terminal to be connected via a network is started, initialization of connection setting is performed in step 100.
That is, various parameters are initialized for the VC that performs communication. See the literature for details on how to set these
[1] (The ATM Forum, Traffic Management Specificati
on 4.0, af-tm-0056.000, April, 1996.) and literature [2]
(The ATM Forum, UNI Signaling Specification 4.0, af
-sig-0061.000, June, 1996). The outline is as follows.

The maximum cell rate (PCR), the minimum cell rate (MCR), and the initial cell rate (ICR) are selected by the connection setting software in the C plane so as to satisfy interface speed ≧ PCR ≧ ICR ≧ MCR ≧ 0. The values of PCR and MCR are set according to the values requested by the upper layer protocol and the provision conditions in the ATM layer. If there are no restrictions from the upper layer protocol and the ATM layer, the interface speed recognized by the device driver is substituted for PCR and 0 is substituted for MCR as default values.

In the case of PVC, the transmittable rate value of the first selected combination table of transmittable rate values and the number of packets that can be transmitted according to the transmittable rate value is substituted for the ICR. In the case of SVC, the ICR value is selected by a signaling protocol. In any case, if ICR> PCR, PCR is substituted for ICR. If ICR <MCR, MCR is substituted for ICR.

The ICR selected above is assigned to the rate holding memory device 52 of the lower layer transmittable rate information simulation function unit 50. Also, a packet number counter device (Packe) in the lower layer transmittable rate information simulation function unit 50.
et Count) 56 includes the count set value Pack
The value of the number of packets read from the first entry of the rate packet table is set as et Count.

Next, if the upper layer protocol function unit 2
If a data packet has arrived from 0, one packet is transmitted and one packet is reduced (steps 102, 1).
04). As a result, if Packet Count becomes 0 (step 106), the lower layer information is updated (step 108).

At step 106, the packet count
If it is determined that t is 1 or more, packet transmission is repeated (steps 102 and 104). On the other hand, if it is determined in step 102 that the data packet has not arrived at the data transmission device 40 'from the upper layer protocol function unit 20, the connection termination request is checked (step 110).

At step 106, the packet count is
When t becomes 0, the lower layer information is updated in step 108 as follows. That is, when updating the transmission rate of the ATM layer, the rate packet table stored in the rate packet table memory device 54 (the transmittable rate value and the corresponding transmittable rate value) in order to simulate the value notified from the ABR service protocol. Combination table consisting of the number of packets that can be transmitted according to the transmittable rate value)
The number of packets and the rate value are read out and written as a new ACR value into the rate holding memory device 52 provided in the device driver.

However, the value to be written as the ACR value is Ma
x (Min (rate value, PCR), MCR) is set. Here, Max (Min (rate value, PCR), MC
R) means that the smaller value of the read rate value and PCR and the larger value of MCR are written as ACR values.

Further, every time an element is read from the rate / packet table, the packet number counter device (Packet Co
Unt) 56 is set to the value of the number of packets read from the rate packet table.

As described in step 104, the value of Packet Count is reduced by the number of packets transmitted when the packet is transmitted from the upper layer protocol function unit 20 to the ATM layer. However, the count value Packet Count must not be smaller than 0. When reading data from the rate packet table, the table may be read in descending order or ascending order, or by using a random number generator, the reading order of table entries may be appropriately changed using random numbers or the like. Is also good. Further, the combination of the number of packets and the rate value may be arbitrarily changed. As the elements described in the rate / packet table, a result obtained by separately performing computer simulation or the like can be used as entry contents. After these processes are completed, packet transmission is repeated (steps 102 to 106).

If it is determined in step 102 that there is no packet to be transmitted, a connection termination request is checked in step 110, and a connection release process is performed in step 116. If it is determined in step 110 that there is no connection termination request, the process proceeds to a transmission packet waiting process (steps 112 and 114).

If a timer is provided, step 1
If it is determined at 12 that a certain period of time has elapsed while waiting for the arrival of the next packet after the arrival of a certain packet from the upper layer protocol function unit 20, the end of the connection is notified at the next step 114. Even before the start, the start value (ICR) of the rate packet table is substituted into the rate holding memory device 52, and the count value Packet C
The process returns to step 102 without changing "out".
If the timer is not used, the process returns to S2.

If there is a connection termination request at step 110, connection release processing is performed at step 116. That is, with the arrival of the connection release request, the entry of the C plane parameter held in the connection is deleted, and the ACR value used as the U plane parameter and the packet are used.
Delete the Count value. By performing the above processing, the upper layer protocol function unit can verify the operation of the upper layer protocol function unit even when the function that the lower layer protocol function unit should originally have is not correctly implemented.

FIG. 7 shows the processing content related to the rate control function of the transmitting terminal in the protocol inspection method according to the second embodiment of the present invention. The protocol inspection method according to the second embodiment differs from the protocol inspection method according to the first embodiment in configuration in that the protocol inspection method according to the first embodiment uses a table including a transmission rate and the number of packets in the first embodiment. The method of dynamically updating the transmission rate has been realized. However, as described in claim 3, the method is realized by using a table based on a set of a transmission rate value and a packet duration. Are the same, and a duplicate description will be omitted. In the present embodiment, as shown in FIG. 7, the packet count value, which is the count setting value of the above-mentioned packet number counter value 56, is not the number of packets but the rate duration time (transmission time) (steps 200 and 208). In the packet transmission process in 202, the lower layer information is updated using a timer every time the timer expires (steps 206 and 208).

FIG. 8 shows the processing content related to the rate control function of the transmitting terminal in the protocol inspection method according to the third embodiment of the present invention. The protocol inspection method according to the third embodiment differs from the protocol inspection methods according to the first and second embodiments in configuration in the following points. That is, in the first embodiment, a method of dynamically updating a rate using a table of a transmission rate and the number of packets is realized, and in the second embodiment, a table of a rate and a rate duration is stored. A method of dynamically updating the rate is realized by using the combination of the transmission rate value and the duration of the packet by using a random number in the third embodiment. This is realized by implementing the above-mentioned steps (step 308 in FIG. 8), and the other configuration is the same, and thus the duplicated description will be omitted.

FIG. 9 shows processing contents related to the rate control function of the transmitting terminal in the protocol inspection method according to the fourth embodiment of the present invention. In the protocol inspection method according to the fourth embodiment, an upper layer protocol is operated on a trial basis without dynamic rate change. For this purpose, the number of packets or the transmittable time of the transmission rate to be read when the output rate that can be transmitted is simulated is set to a specific value that is not used for displaying the number of packets or the transmittable time. By doing so, the function of notifying by dynamically changing the transmittable rate value is stopped.

More specifically, as shown in FIG.
1. The number of packets in the rate / packet table entry is set to 0 by the algorithm (FIGS. 6 and 7) in the second embodiment, and if the number of packets is 0 immediately before performing step 404, step 404 and subsequent steps are performed. This can be realized by incorporating an algorithm (steps 402, 412 to 414) that does not execute the processing but always keeps the same rate value as the ACR value until the end of the connection.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications within the technical scope.

[0049]

According to the first to fifth aspects of the present invention,
Instead of actually operating the lower layer protocol, an output rate that can be transmitted by the lower layer protocol is simulated, and the generated output rate is notified to the upper layer so that the upper layer can be transmitted without actually implementing the lower layer protocol. Since the layer protocol was tested,
The test of the upper layer protocol can be performed without waiting for the complete implementation of the lower layer protocol, and the completeness of the protocol can be quickly increased.

It is also possible to judge the required conditions from the upper layer protocol side regarding the functions to be provided in the lower layer protocol and the accuracy thereof.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a basic configuration of an ATM communication network to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a functional model in a transmission terminal to which the present invention can be applied.

FIG. 3 is a block diagram showing a functional configuration of a transmitting terminal to which the present invention is applied.

FIG. 4 is a block diagram showing a configuration between devices related to ATM layer control in a transmitting terminal.

FIG. 5 is an explanatory diagram showing a specific example of the contents of a rate packet table.

FIG. 6 is a flowchart showing control contents related to ATM layer control according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing control contents related to ATM layer control according to a second embodiment of the present invention.

FIG. 8 is a flowchart showing control contents related to ATM layer control according to a third embodiment of the present invention.

FIG. 9 is a flowchart showing control contents related to ATM layer control according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10-1 and 10-2 Communication terminal 12 ATM communication network 14 ATM switch 20 Upper layer protocol function unit 40 'Data transmission device 50 Lower layer transmittable rate information simulation function unit 52 Rate holding memory device 54 Rate / packet table memory Device 56 Packet number counter device 58 Control device

Continuation of front page (56) References JP-A-5-95376 (JP, A) JP-A-3-16352 (JP, A) JP-A-6-268719 (JP, A) JP-A-3-295339 (JP) JP-A-10-336202 (JP, A) JP-A-10-285252 (JP, A) JP-A-5-160880 (JP, A) JP-A-5-191476 (JP, A) JP2000 −32056 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 29/14 H04L 12/56

Claims (5)

(57) [Claims] 1. A communication which is hierarchized by function and divided into layers in a terminal device connected to a network having an explicit congestion notification, an explicit transmittable rate notification or a transmittable data amount notification function for a transmitting terminal. A protocol inspection method that uses a protocol and inspects operating characteristics of an upper layer protocol located on the lower layer protocol when an output rate that can be transmitted in a lower layer protocol part located lower is dynamically changed. Instead of actually operating the lower layer protocol, the output rate that can be transmitted by the lower layer protocol is simulated, and the generated output rate is notified to the upper layer so that the lower layer protocol is not actually implemented. Pro-Turkish inspection method characterized by performing a test of an upper layer protocol 2. The method according to claim 1, wherein when the output rate that can be transmitted is simulated, the output rate is generated in advance by transmitting a lower layer rate value that can be transmitted in units of an upper layer packet and the rate value. 2. The protocol inspection method according to claim 1, wherein the method is implemented by reading a set of good packet numbers as a table. 3. The method according to claim 1, wherein when the output rate that can be transmitted is simulated, the output rate is generated by transmitting a lower layer rate value that can be transmitted in advance in units of an upper layer packet and the rate value. 2. The protocol inspection method according to claim 1, wherein the protocol inspection method is realized by reading a set of good transmission possible times as a table and switching transmission possible rate information when the transmission possible time is reached. 4. A method for generating a transmittable output rate by simulating the transmittable output rate, including generating a transmittable rate value using a random number, and setting a duration of the transmittable rate value to a random number. The protocol inspection method according to claim 1, wherein the determination is performed using the protocol. 5. A method for setting the number of packets or the transmittable time of the read rate to be simulated to generate the transmittable output rate to a specific numerical value which is not used for displaying the normal packet number or the transmittable time. 4. The protocol inspection method according to claim 1, wherein the function of dynamically changing the transmittable rate value and notifying the value is stopped.