From: sanjay@socs.uts.edu.au (Sanjay Jha)
Subject: Overview of SMP drafts.
Keywords: smp
Organization: Computing Sciences, Uni of Technology, Sydney.
Date: 10 Nov 92 09:29:35 GMT


OVERVIEW OF SIMPLE MANAGEMENT PROTOCOL

One of the major concerns of the networking community is regarding the future relevance of TCP/IP with respect to OSI. Where one section strongly advocates the use of OSI protocols, there are many others who having worked hard and successfully on Internet are trying to solve the new problems within the existing framework.Simple Management Protocol is the next generation in the genus of Management framework originally derived from Simple Gateway Monitoring Protocol.(SGMP).The following describes the various


 components of SMP framework.
i) SMI:MIB modules are written using a subset of OSI's ASN.1. Structure of Management Information(SMI) defines this subset. ASN.1 macro  is used to convey the syntax and semantics of object definitions, trap definitions and agent capabilities. Macro definition notation(MDN) provides users a mechanism to extend the notation for their own use or for use by other users.

ii)Textual Conventions: When designing a MIB module, it is often useful to define types, with a different name, but the same syntax, as one of the typesdefined in SMI. These are termed textual conventions and are used for the convenience of human reading of the MIB module. Textual conventions draft for SMP defines the initial set of textual conventions available to all modules.

iii)Protocol Operations: The draft Protocol Operations for SMP defines the operations of the protocol with respect to the sending and receiving PDUs. Two additional PDUs alongwith existing  PDUs of SNMP overcome some of the major weaknesses of SNMP. The GetBulkRequest-PDU minimizes the number of protocol exchanges required to retrieve a large amount of management information.The InformRequest-PDU facilitates manager to manager communication.

iV)Transport mappings: SMP may be used over a variety of protocol  suites. A set of initial transport mappings e.g. SMP over OSI, SMP over DDP, SMP over UDP, SMP over IPX has been defined in the Transport mapping draft. The mapping onto UDP is the preferred one out of these. As such to provide greater level of interoperability systems choose to deploy other mappings should also provide for proxy service to UDP mapping.

V)Protocol Instrumentation : Managed objects which describe the behavior of  a SMP entity have been defined in  the draft Management Information base for SMP. The manager to manager MIB for SMP defines the initial set  of managed objects which describe the behavior of SMP entity which acts in a manager role.

Vi)Administrative framework: The administrative framework used for SMP is based on the administrative framework defined in rfc1351 with some modifications. SMP used a modified Digest Authentication Protocol smpMD5AuthProtocol which improves the performance and security aspects over SNMP.

To achieve coexistence at the protocol level, a protocol entity acting in a manager role might support both SNMP and SMP. When a management application needs to contact a protocol entity acting in an agent role , the entity acting  in a manager role consults a local database to select correct management protocol to use.(See the Snmp/Smp coexistence draft for details)

Internet drafts containing information on SMP are just work in progress.If accepted by the industry, SMP will provide a strong alternative to OSI based management protocols.
(I have tried to provide a gist of drafts on SMP by Case,McCloghrie, Rose and Waldbusser which can be obtained from various servers using ftp.)
--

  Sanjay Kumar Jha          E-mail: sanjay@socs.uts.edu.au
  Address:9/42,The Avenue, Hurstville,NSW-2220, AUSTRALIA.         
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Newsgroups: comp.protocols.snmp