tagging traffic issues OR not

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Jan 16th, 2009
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Hi all, To be short, I had a small disagreement with a colleague about some issues we were having with our IP phones, Basically all the IP phones stopped working at certain intervals. At this tim we saw FCS errors on the main port into the phone system. I changed the port to AutoNeg and this seemed to have solved the problem, however they are saying it was nothing to do with that and it ws the tagging on the uplink ports, basically at this site they were a set of Nortel switches, with the uplink port set to untagpvidonly, which allows for a native vlan on the trunk same as per normal on a cisco switch. however we have another site with te setting Tag all on the trunk which tags all traffic,they had no issues there, but the port was already on autoneg.

They are saying it was not the autoneg but the tagging on the uplink port between the switches.

My question is what has this got to do with the port connecting to the phone system getting FCS errors, noting in my case. At the site affected, it was working with the native vlan on the uplink ports for months before, this only happend when they changed the card in the phone system.

Your thoughts please



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Giuseppe Larosa Fri, 01/16/2009 - 03:46
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Hello Carl,

if there was a problem with Vlan tagging it would have been a persistent problem not intermittent: the phones would have been out of service always not usable for some time then unusable and again.

This is enough to agree with your analysis.

Hope to help



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