[c-nsp] SNR Values: wic1-shdsl v2

[Alistair Cockeram]

I've got two wic1-shdsl v2 wic cards in a 1721 chassis running:

Cisco IOS Software, C1700 Software (C1700-SY7-M), Version 12.3(4)XG3,
RELEASE S)
Synched to technology version 12.3(5.7)T

when I do show controllers dsl 0 or 1 

both cards report SNR values of:

SNR Sampling:  31.8680 dB (dsl 0)

SNR Sampling:  31.6790 dB (dsl 1)

These figures appear to be incorrect as the DSLAM is reporting:

(dsl 0) SNR dowm 16dB  up 9dB

(dsl 1) SNR down 17dB  up 9dB

These are two different sdsl circuits to the same building. 

The attenuation figures for both circuits are shown correctly. A quick
google reveals nothing and I'm wondering if this is a bug or if I'm miss
reading the results. There is more than +/-4dB difference between the
dslam and the cards so I don't believe this is related to:

http://www.cisco.com/warp/public/770/fn26014.shtml (which is for a
different IOS version anyway).

Testing a wic1-adsl card in another 1721 on a different adsl circuit reveals 
the correct readings reported for SNR from the router and the dslam.

Any ideas? Obviously it is fairly useful to have correct figures when
checking SNR in the field.

-- 
Alistair Cockeram, Hebden Bridge UK
"Everyone around me dies, Mr. Morden, except those who most deserve it."