Dear Koo,
We have a similar situation in our network, where we monitor the utilisation
with the
same variables (ifInOctets and ifOutOctets) over WAN leased (serial) lines.
We have
Cisco 7513 routers (at the central office) and Cisco 2516 (at the remote
sites).
As an NMS, we use IBM NetView 4.1 with AIX 4.1.5
We use encapsulation ppp on the lines and we apply PPP compression as
well (via compress predictor command applied at both ends of the WAN
link). What we monitor is the compressed traffic over the WAN lines.
I' m sure of that because I also monitor the uncompressed traffic which ends
to the remote ethernet-based offices. If you can't see the compressed
traffic from your NMS it is maybe because compression was never applied to
your
serial interfaces at all !!!! (Note that compression must be applied to
both ends
of the WAN link. If it is applied only at one side it is ignored by the
routers).
If you apply the compression PPP the way I described you can check on the
compression rate by applying the following command (either to the remote or
the central router):
router# sh compress
Check also the variables locIfInBitsSec and locIfOutBitsSec which are
provided by
the Cisco MIB (under subtree local).
Hopes this helps,
Kostas Kottos,
ASYK
-----Original Message-----
From: Koo Lawrence <lkoo@WOOLWORTHS.COM.AU>
Date: P]lptg, 3 Dejelbq_ou 1998 12:46 pl
Subject: NMS data collection on true bandwidth for compressed data on seri
al WAN links
>Hi there,
>
>We are monitoring how our WAN links' bandwidth are utilised by performing
>data collection from our NMS the MIB variables ifInOctets and ifOutOctets.
>Since we are using compression services, be it hardware compression with
CSA
>or software compression, the data collected by NMS from the MIB information
>repository on Cisco is the decompressed value. This means that the data is
>not a true representation of the bandwidth chewed up on the links but
rather
>a larger value after decompression.
>
>The questions are: is there any easy way we can get the true bandwidth
>utilisation information on the compressed data? If not, what's the channel
>to make a request to Cisco to provide such information in the MIB
>repository, and report on the compression ratio for every serial link and
>store it in the MIB repository?
>
>Any help will be highly appreciated.
>
>Regards,
>Lawrence
>
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