Internet DRAFT - draft-mahesh-netconf-persistent
draft-mahesh-netconf-persistent
Network Working Group M. Jethanandani
Internet-Draft Ciena Corporation
Intended status: Standards Track October 27, 2014
Expires: April 30, 2015
NETCONF and persistent responses
draft-mahesh-netconf-persistent-00
Abstract
This document outlines a solution for NETCONF operations that might
be initiated with a single request but require multiple responses to
be received, with an ability to terminate the operation at any time.
Status of This Memo
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This Internet-Draft will expire on April 30, 2015.
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1. Introduction
NETCONF [RFC6241] protocol is being positioned as a replacement for
Command Line Interface (CLI) and Simple Network Management Protocol
(SNMP). It is therefore expected that NETCONF will provide all the
capabilities that CLI and SNMP offer today and more.
One of the operations that CLI offers today is the ability to issue
an operation that might result in multiple responses being returned,
till such time that a terminaing condition is encountered or when the
operation is cancelled. An example of such an operation is when the
ping or a traceroute command is issued. In the former case, the
operation can continue sending responses back till it is cancelled,
while in the latter case there is usually a terminating condition
that stops the responses. NETCONF protocol as defined today sends a
single Remote Procedure Call (RPC) request and expects a single reply
to that request. The "persistent" operation defined above expects
multiple responses for a single request, till such time a terminating
condition is encountered.
This problem should not be confused with "bulk responses" where one
might be dealing with fragments of the same response. It is not
enough to have the server collect all the possible responses before
responding because in some cases there may not be a response,
indicating a failure and it will hold up the NETCONF session till a
response is received.
Section 2 suggest at least one solution to this problem.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in Key words for use in
RFCs to Indicate Requirement Levels [RFC2119].
1.1. Terminology
+---------+------------------------------------+
| Acronym | Meaning |
+---------+------------------------------------+
| CLI | Command Line Interface |
| | |
| RPC | Remote Procedure Call |
| | |
| SNMP | Simple Network Management Protocol |
+---------+------------------------------------+
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2. Solution
The proper solution should address the requirement of multiple
responses, fragmented responses and an ability to terminate the
request without terminating the NETCONF session. This can be best
achieved at the messaging layer in NETCONF, where a single request
can result in multiple responses being received and way to associate
the multiple responses with the original request.
One of the suggested solutions would look like this. A request goes
out with the operation to perform.
<rpc message-id="101" link-id="201" xmlns="...">
</rpc>
And a reply can come back with either a <rpc-reply> as it happens
today or a series of "linked replies" which would look like this.
<rpc-reply message-id="101" next-message-id="102" link-id="201"
xmlns="...">
</rpc-reply>
<rpc-reply message-id="102" next-message-id="103" link-id="201"
xmlns="...">
</rpc-reply>
with the last reply looking like this.
<rpc-reply message-id="101" message-id="103" link-id="201"
xmlns="...">
</rpc-reply>
When the client wants to terminate the task, it issues an <rpc-
cancel> to terminate the condition. Note, NETCONF currently does not
support this particular operation.
<rpc-cancel link-id="201">
</rpc-cancel>
And a reply comes back acknowledging that the task was terminated.
<rpc-reply>
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<ok/>
</rpc-reply>
3. IANA Considerations
4. Security Considerations
5. Acknowledgements
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
Bierman, "Network Configuration Protocol (NETCONF)", RFC
6241, June 2011.
6.2. Informative References
[RFC6243] Bierman, A. and B. Lengyel, "With-defaults Capability for
NETCONF", RFC 6243, June 2011.
Author's Address
Mahesh Jethanandani
Ciena Corporation
3939 North 1st Street
San Jose, CA 95134
USA
Phone: 408.904.2160
Fax: 408.436.5582
Email: mjethanandani@gmail.com
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