The MPLS WG Archive

["Choudhury, Sanjaya" <Sanjaya.Choudhury@marconi.com>]

one follow-up question inline ...

-----Original Message-----
From: Thomas Nadeau [mailto:tnadeau@cisco.com]
Sent: Monday, September 24, 2001 1:22 PM
To: Choudhury, Sanjaya
Cc: mpls@UU.NET
Subject: Re: Questions / Comments on MPLS-TE MIB



>         Hi! Here are few questions/comments related to MPLS-TE MIB.
>         Your help will be appreciated.
>
>         Thanks,
>         sanjay
>
>         1. mplsTunnelInstancePriority, is significant only in the context
>         of a Tunnel (group of tunnel instances).
>
>         Therefore, according to the MPLS-TE model,load sharing and
>         failover(primay-backup) mechanisms are valid ONLY within a
>         Tunnel and not across Tunnels.
>
>         Is this the correct interpretation of the MIB ?

         Yes, the tunnelInstancePriority is significant only
within the tunnel instances using the same first index of
the tunnelEntry.

>         2. Currently, the MPLS-TE MIB does not allow the user to
>         specify the traffic class (ex. DiffServ class) associated with
>         the Tunnel Instances.
>
>         Although, one can define new MIBs to add the above mentioned
>         feature, in my opinion, extending the existing (pre-RFC) MPLS-TE
>         BIB, will significantly enhance the usability of the MIB.
>
>         Can/Should this be done?

         This has already been done. The DiffServ Packet
Classifier MIB can be used to handle the DiffServ
marking/matching operation. Once this operation is
done, a packet is ultimately dropped or forwarded. If
it is forwarded, it should arrive at the MPLS FTN MIB.
The MPLS-FTN-MIB allows one to associate incoming traffic
with a tunnel interface.
	
	I am assuming that by 'DiffServ Packet Classifier MIB'
	you referring to the DiffServ MIB defined by the DiffServ
	working group.

	Besides mapping the traffic to the tunnels (/tunnel
	instances), one need the know the traffic class associated
	with traffic tunnels for the following purposes:
		1) To signal the PSC associated with the 
		   tunnelInstance (L-LSPs)

		2) To do a sensible interpretation of 
		tunnelInstancePriority for load sharing 
		and failover (primary - backup) mechanism.
		[Example: 
			Two tunnel instances, one EF and
			another AF, having same tunnelInstance
			Priority, supported ???
		] 

	How can these be handled by the DiffServ MIB ? 

	Thanks,
	sanjay


>         3. If you add the traffic class support to the mplsTunnelTable,
>         should this trafficClass be an (additional) index to the tunnel
>table ?
>
>         i.e. Should all the instances of a traffic tunnel have the same
>         traffic class ?

         I think that is implementation dependent. However, I would
think that which ever LSP (instance) of that tunnel is used to carry
that traffic should probably be specified in such a way as to satisfy
the needs of the traffic, but I am not sure that is a hard
requirement.

         --Tom