CN1209894C

CN1209894C - Reliable message transmitting method of simple network management protocol

Info

Publication number: CN1209894C
Application number: CN 01131969
Authority: CN
Inventors: 魏丽红; 郭南; 钟军辉; 王潮; 陈伟杰; 徐海东; 万水鱼
Original assignee: Eastern Communication Co Ltd
Current assignee: Eastern Communication Co Ltd
Priority date: 2001-10-15
Filing date: 2001-10-15
Publication date: 2005-07-06
Anticipated expiration: 2021-10-15
Also published as: CN1350385A

Abstract

The present invention relates to a method for reliably transmitting messages in a simple network management protocol, which aims to solve the problem of packet loss in remote transmission and make a network management center capable of accurately receiving warning messages sent by a system in which a managed device is positioned in time. An original structural system does not need to be changed, and only network management servers of a local SNMP managed system and a remote SNMP managing system are respectively provided with a UDP/TCP conversion client end and a UDP/TCP conversion server. When the managed system generates a Trap event, after the UDP/TCP conversion client end receives an SNMPTrap message encapsulated by a UDP protocol, the SNMPTrap message is converted from a UDP format into a TCP format and sent to the UDP/TCP conversion servers of the managing system; the UDP/TCP conversion server reversely converts the message which is in the TCP format into a message which is in the UDP format and sends the message to the managing system; in this way, TCP conversation transmission between a local network management server and a remote network management server is realized. The method is applied to reliably monitor the SNMPTrap message transmission of one piece of monitored equipment or a plurality of pieces of monitored equipment.

Description

The method of message reliable transmission in the Simple Network Management Protocol

Technical field:

The invention belongs to the fault management in the network management of internet, relate to SNMP Trapv1/v2 message (fault message) reliable transmission, with the technology of software function module control.

As everyone knows, at the end of the eighties, the Internet and other Affiliate Networks develop rapidly, and be also growing to the necessity of network management.SNMP has obtained sizable achievement, the NMP standard on coming true because it is simple in structure, implement characteristic easily in research and commercial field.At present, internet device (Router, Ethernet Switch etc.) etc. is realized the fault management of the equipment of network management based on snmp protocol, the relevant regulation of RFC is generally abideed by by each equipment vendors, by Trap mechanism, will contain the Trap message active report network management system of fault message.What adopt in the SNMP system is the model of " manager/agent device ", in the transmission to the encapsulation of Trap message, employing be UDP and IP agreement.Architecture from the Trap information of managed network equipment, is acted on behalf of through SNMP as shown in Figure 1, after the UDP/IP encapsulation, transmit by network, arrive supervising the network, after removing the UDP/IP header of encapsulation, submit to management application software through the Trap information of snmp management device reduction.

In TCP/IP protocol suite, exist towards connecting and connectionless agreement.

Connection-oriented Protocol is used to set up and safeguards connection between the computer of mutual communication and the state that should connect in the monitor message transmission course.Each packet that sends on network all can receive the receipt that a other side sends, and state information under the computer recording of transmitting terminal is received by the other side like clockwork to guarantee each data.When message transmission finishes, close to the computer security of transmitting terminal and receiving terminal and be connected.

Connectionless protocol is used for sending the one-way data newspaper to the destination, but and the computer data of no advice (NA) destination just on transmission path.The purpose computer receives the data that the other side sends, but the state information of the data that receive is not returned to source computer.

TCP belongs to Connection-oriented Protocol, and UDP belongs to connectionless agreement.The form of their packet is as follows respectively:

Tcp data newspaper form

Source port	Destination interface
Source port	Destination interface	Sequence number
Confirm number		Sequence number
Confirm number		Data offset
Reserved field		Data offset
Reserved field		The flag bit field
Window		The flag bit field
Window		Verification and
Urgent indication code		Verification and
Urgent indication code		Option
Filler		Option
Filler		Data

● source port: the port numbers of distributing to the application program on the source computer; ● destination interface: the port numbers of distributing to the application program on the purpose computer; ● sequence number: identify the numerical value that is provided with in first byte of data in the current message.In the stage of connecting, this territory also is used for being identified at initialization sequence that the transmission that will carry out uses number; ● confirm number: the number that is used to confirm to receive data segment.This value is the Next Sequence that the computer expectation will receive, the i.e. sequence number of last that receive oneself+1; ● data offset: tell how much length of receiving terminal head is, promptly real data are from where; ● reserved field: giving in the future and use, to adapt to the needs that TCP develops in the future, is reserve area at present, all is 0; ● flag bit field: carry various control informations, comprise that the SYN that is used to connect is with the ACK position and be used to the FIN position of finishing to be connected; ● window: be used to carry out the parameter of current control, specify sender's receive window size, just can be used for receiving between the buffer empty of data; ● verification and: be used to a territory checking that data segment is complete.Receiving end computer is carried out according to data segment and is checked and calculating, and the value of calculating is compared with there being the value in this territory, to check the integrality of data segment; ● urgent indication code: point to first emergency data byte in the packet; ● option; Specify the variety of option of TCP; ● filler: some extra 0 (using as required), to guarantee that data are since one 32 bit boundary place; ● data: the data that send, from the information on upper strata.

The UDP datagram form

Source port	Destination interface
Source port	Destination interface	Length
Verification and		Length
Verification and		Data

● source port: the udp port of the application program that sends datagram number; ● destination interface: the port address that the UDP software of receiving end computer sends to data; ● length: specify the common length of UDP head and data, the length of promptly whole UDP datagram; ● verification and: be used for specified data newspaper and whether make mistakes in transmission course; ● data: the data that send, from the information on upper strata.Snmp protocol belongs to the application layer in the ICP/IP protocol group, is operated on the udp protocol.Communicated by UDP between network manager and the quilt pipe agency.Because the UDP/IP agreement is towards the disconnected connectionless data transport service that provides, guarantee so in the transmission of message, lack reliability.If distributed far away physically by managed object in the guard system and network management system, packet loss phenomenon in then being very easy to occur transmitting, cause losing of Trap information, make the accuracy of fault management and real-time not to be guaranteed, this is the problem that network management need solve.

Summary of the invention:

The present invention is directed to prior art problems, is in order to solve the packet loss problem in the remote transmission, to guarantee the reliable transmission of SNMP Trap message, makes network management center can receive the warning information that managed device place system sends up accurately and timely.

Method of the present invention is to carry out on original SNMP architecture basis, be characterized in dress UDP/TCP conversion client on the local terminal NM server, dress UDP/TCP change server on the far-end NM server, when local terminal SNMP is produced the Trap incident by management system, its UDP/TCP conversion client is behind the SNMP Trap message of receiving the udp protocol encapsulation, become the TCP form to mail to the UDP/TCP conversion traffic device of far-end snmp management system the UDP format conversion, convert the message of TCP form to UDP form message by change server then and be sent to management system, realize the TCP session transmissions between local terminal and two NM servers of fortune end.

Remarkable advantage of the present invention is to guarantee that warning information can packet loss when long-distance is delivered, and can accurately be received by the far-end NM server, realizes the telecommunication network reliably monitoring, the network management that can effectively assist the webmaster personnel of the Internet.

Description of drawings:

Fig. 1 is conventional snmp management model schematic flow diagram;

Fig. 2 is that the present invention is single by transfer process schematic diagram in the long-distance management system of guard system;

Fig. 3 is that the present invention is a plurality of by the large-scale management system transfer process schematic diagram of tube system;

Fig. 4 is the schematic flow sheet of local terminal UDP/TCP conversion client;

Fig. 5 is the schematic flow sheet of far-end UDP/TCP change server;

Fig. 6 is far-end UDP/TCP change server and extraneous interface schematic diagram;

Fig. 7 is local terminal UDP/TCP conversion client and extraneous interface schematic diagram;

Fig. 8 is a software module schematic flow sheet of the present invention;

Fig. 9 is a structure connection diagram of the present invention.

Embodiment:

With reference to the embodiment of description of drawings the inventive method,, on local terminal and far-end NM server, UDP/TCP conversion client and UDP/TCP change server module are installed respectively as Fig. 2 or shown in Figure 3.The UDP/TCP conversion client is finished the transfer process that UDP wraps the TCP bag, and the UDP/TCP Transformation Service is finished the reverse conversion process that TCP wraps the UDP bag, it is transmitted with the form of TCP bag on the net at Internet, to guarantee that fault warning information can not lose when the long-range delivery, can guarantee accurately to be received by the far-end NM server.

The UDP/TCP conversion client is to finish the message that converts the TCP form from the Trap message of the UDP form that flowed into by management system to, be sent to the UDP/TCP change server that has connected, realize the conversion of SNMP Trap V2 to SNMP Trap V1 version, transfer standard is with reference to RFC1908.Wherein total interface is all realized by Socket, the UDP/TCP conversion client have 2 with extraneous interactive interface as shown in Figure 6.Wherein 162 ports and transient port content description are as follows:

Port numbers	Protocol type	Describe	Other
Port numbers	Protocol type	Describe	Other	162	UDP	Receive the Trap incident	Trap (TRAP) receiving port of SNMP acquiescence
Transient port	TCP	Give server with the Trap transfer of data	When this port is connected by system, binding automatically;	162	UDP	Receive the Trap incident	Trap (TRAP) receiving port of SNMP acquiescence

Communication format on 162 ports is a SNMP v1/v2 version form, and the communication format on the transient port is as follows:

A transmission frame

The local network header

The IP header

The TCP header

SNMP Trap v1 message

The local network telegram end

The UDP/TCP change server is will finish the TCP message that is produced by the UDP/TCP conversion client that flows into from Internet to convert the UDP message to and be sent to management system; And the connection of a plurality of conversion client managed.Total interface also realizes two external tappings being arranged as shown in Figure 7 by Socket.

Interface is described:

Port numbers	Protocol type	Describe	Other
Port numbers	Protocol type	Describe	Other	Transient port	UDP	Send the Trap incident	When this port is sent by system, binding automatically, the user need not be concerned about; The destination interface that sends can arrange default 162 with " management system "
Serve port	TCP	Reception Internet goes up the transfer of data from " conversion client "	Port numbers user is pre-defined, uses when client connects.	Transient port	UDP	Send the Trap incident

^*The TRAP receiving port of SNMP acquiescence is 162.

Communication format on the transient port is the SNMP v1 version form of standard; Communication format on the serve port is as follows:

A transmission frame

The local network header

The IP header

The TCP header

SNMP Trap v1 message

The local network telegram end

The realization flow of UDP/TCP conversion client and UDP/TCP change server respectively as shown in Figure 4 and Figure 5.

Implementation process is described below:

■ starts " UDP/TCP change server " earlier, starts simultaneously " UDP/TCP conversion client ", and establishes a communications link with server:

The Trap transmission object of ■ " by management system " all is configured to point to " the UDP/TCP conversion client " at local network;

When ■ produces the Trap incident when " by management system ", " UDP/TCP conversion client " receives this message, then, become the TCP form to mail to " UDP/TCP change server " by the UDP format conversion message, server is reduced into the UDP form with message after receiving, and sends to the Trap incident receiving port of " management system ".

The connection transmission relation of software module of the present invention as shown in Figure 8.The UDP/TCP conversion client is considered as local terminal and transmits control desk among the figure, and the UDP/TCP change server is considered as far-end and transmits control desk, and control desk is transmitted in the general designation alarm.In Fig. 8, SNMP Trap message from many monitored devices is sent to local terminal forwarding control desk in the UDP mode, local terminal is transmitted control desk and is finished UDP after the protocol conversion of TCP ground, and set up the TCP session between the far-end forwarding control desk, the Trap message is transmitted to far-end transmits control desk, far-end is transmitted control desk and is carried out TCP once more after the protocol conversion of UDP, the Trap message is forwarded to respectively alarms client, finishes the process that whole alarm is transmitted.

Fig. 9 represents the annexation of each parts.Local terminal is transmitted control desk can be installed in local network management center, receives the warning information of local managed device, as equipment such as router, Ethernet switch, VOIP gatekeeper, dns servers.Far-end is transmitted the network management center that control desk can be installed in upper level, receives the warning information that network management center of subordinate sends up.

The operation of system does not have special soft, hardware requirement, and hardware needs 100/10M network interface card, operation platform to can be WindowsNT/98, sun OS 5.X, Linux 6.x etc.

Claims

1. the method for message reliable transmission in the Simple Network Management Protocol, it is characterized in that dress UDP/TCP conversion client on the local terminal NM server, dress UDP/TCP change server on the far-end NM server, when local terminal SNMP is produced the Trap incident by management system, its UDP/TCP conversion client is behind the SNMP Trap message of receiving the udp protocol encapsulation, become the TCP form to mail to the UDP/TCP change server of far-end snmp management system the UDP format conversion, by this change server the message that the message of TCP form converts the UDP form to is sent to management system again, realizes the TCP session transmissions between local terminal and two NM servers of far-end.