The MPLS WG Archive

["Adrian Farrel" <afarrel@movaz.com>]

Thanks,
That's very helpful.

I'll massage it and work it. If I have any issues or questions, I'll come back
to you.

Adrian
----- Original Message -----
From: "Sharon Chisholm" <schishol@nortelnetworks.com>
To: <mpls@UU.NET>
Sent: Monday, December 16, 2002 10:36 AM
Subject: Text for Management Overview Document


> hi
>
> In the MPLS MIB meeting in Atlanta, I promised to provide
> some text for the management overview document to help
> demystify the MIBs for general applications trying to
> discover and manage LSPs.
>
> There are still a few aspects I'm not 100% sure of, so
> I suspect some cleanup of the text will be required.
>
> ---------
> N. LSP Discovery and Management
>
> There are three different types of LSPs in MPLS -
> Traffic Engineering Tunnels, LDP and single hop
> service LSPs. Each of these will be discovered
> and managed somewhat differently.
>
> N.1. Traffic Engineering LSPs
>
> Traffic engineering LSPs are frequently explicitly
> routed and tend to be fairly persistent so can
> therefore be managed using techniques similar to
> that of connection oriented systems.
>
> These links can be discovered by reading in the
> interface table and matching against entries with
> an ifType of mplsTunnel(150). Under normal operation,
> ifConnectorPresent will always have a value of 'true'.
> As the operational status of these links is
> service affecting, ifLinkUpDownTrapEnable should
> be changed from its default value of 'false'
> to be 'true'.
>
> Additional information about this type of LSP can be
> found in the MPLS LSR MIB and the MPLS Traffic
> Engineering MIB.
>
> N.2. Label Distribution Protocol (LDP) LSPs
>
> LDP LSPs are implicitly routed LSPs and therefore
> most closely resembles traditional routing protocols,
> but, unlike protocols like BGP, the components of
> the LSP are found in the interfaces table.
>
> Both active and redundant links can be discovered by
> reading in the interface table and matching against entries with
> an ifType of mpls (166).  A value of 'true' for ifConnectorPresent
> indicates that a link is active. Given the redundancy of
> links as well as the potential for non-service affecting
> changes in the operational status of component links, it
> does not really make sense to monitor these interfaces for
> linkDown notifications, so ifLinkUpDownTrapEnable has a
> default value of disabled for this type of interface.
>
> Additional information about this type of LSP can be
> found in the MPLS LSR MIB and the MPLS LDP MIB.
>
> N.3. Single Hop Service LSPs
>
> At the service level, there is a third type of LSPs in
> single hop service LSPs (e.g. 2547 BGP, or extended
> LDP discovery). It is not a peer layer to TE and
> LDP, but an overlay.
>
> This type of LSP shows up in the interface table
> as interfaces with ifType of mplsTunnel(150) layered
> over interfaces with ifType of mpls(166). The ifStack
> table will show the layering relationship between
> the LSPs.
>
> Additional information about this type of LSP can be
> found in the MPLS LSR MIB, the MPLS LDP MIB and the
> MPLS TE MIB.
> -----
>
> Sharon Chisholm
> Portfolio Integration
> Nortel Networks
> Ottawa, Canada