The MPLS WG Archive

["Vipul Sharma" <vsharma@senecanetworks.com>]

Shahram,
	I had run into similar question a while ago...Attached is the info. which
will help you for 1.
My feeling is that since there is no error conditions maybe they need to be
collected in mplsInSegmentDiscards. But that is just what I beleive maybe
the gurus have a differing opinion.
For 2, I believe that we are reqd. to keep 2 sets of stats one for the
swapped label and one for the pushed label
	Thanx,
Vip
vsharma@ieee.org

Attached message
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>         In the MPLS MIBs (MPLS TE , MPLS LSR MIBs)I see stats for errored
> packets.
>For e.g. in the MPLS LSR MIB there is mplsInSegmentErrors which is "The
>number of errored packets received on this segment."
>         My question is what type of errors make these packets errored
packets
>because most errored packets are dropped at the physical interface iteself
>by the chips (my understanding). So does this stats put a req. to run the
>phy. interface device in promiscous mode?

         Basically any case where a labeled packet is received and
cannot be forwarded by the MPLS software. There are many cases:
out of bandwidth in the switching fabric, illegal labels in the
packet, etc...


         --Tom




>Vip
>

-----Original Message-----
From: owner-mpls@UU.NET [mailto:owner-mpls@UU.NET]On Behalf Of S. Davari
Sent: Monday, June 11, 2001 6:42 PM
To: mpls@UU.NET
Subject: LSR-MIB Question


Hi All,

A few questions regarding LSR-MIB:

1) If TTL expires in an MPLS packet is the packet
counted in
mplsInSegmentErrors" or not?

2) If we receive a labeled packet and swap the label
and then push a new label
do we keep 2 sets of statistics on the outgoing
segment, one for the swapped
label and one for the pushed label or only one?

BTW, I also noticed that in LSR-MIB a swap consists of
a pop on incoming segment followed
by a push on outgoing segment, this is odd !! The
odder thing is that the incoming segment has
a parameter called InSegmentNpop in which "N"
identifies the number of pops to be performed on the
insegment. How does one know in advance how many pops
to perform? If you know that, then it means
that all those labels that you pop are not used at
all.

Thanks,
-Shahram

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• From: "Vipul Sharma" <vsharma@senecanetworks.com>
• Date: Fri, 4 May 2001 11:36:58 -0400
• Importance: Normal
• X-scanner: echelon

It is my understanding that both stats are to be collected to satisfy the
LSR MIB.
Each LSR is reqd. to collect stats for in-segments and out-segments on a per
LSP basis. In case of a tunnel, it should collect stats on per LSP (which
may be agg. in a tunnel) as well as the tunnel (which is a new LSP)from a
LSR point of view.
Atleast, this is my understanding....

Vip

-----Original Message-----
From: owner-mpls@UU.NET [mailto:owner-mpls@UU.NET]On Behalf Of Shahram
Davari
Sent: Friday, May 04, 2001 11:03 AM
To: 'mpls@uu.net'
Subject: LSR MIB question


Hi All,

If an LSR is the origin point of an MPLS tunnel, and it receives an MPLS
packet, it first swaps the top label and pushes a new label on top of that.
Which performance statistics are required to be collected by LSR-MIB: The
swapped label or the pushed label or both?

Yours,
Shahram Davari

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