Cisco Not playing nice with iP phones

Alan McConnaughey

Hello,

I have a weird problem. My Cisco Small Business SG 300 switches don't play nice with our Allworx Sip phones. The quality is downright bad. If I first connect the phone to another switch (adtran Nvanta) or dumb netgear unmanaged switch then the call quality is just fine. As the traffic is passing through the cisco eventually I don't understand why the quality improves.

Anyone have any ideas on how to solve this problem?

Thanks

Alan McConnaughey

I think it might be the Default QOS settings. I have disabled QOS to see if that make it better or worse.

Ronnie Wong

@Alan-McConnaughey ,

There may be a few issues here but try set the voice vlan id,:

(config)#voice vlan id XXX
(config)#voice vlan state auto-enabled
(config)#interface range fax-xx
(config-if-range)#switchport trunk native vlan XXX
(config-if-range)#switchport trunk allowed vlan add XXX

See more at: https://supportforums.cisco.com/discussion/11380886/need-help-configuring-voice-vlan-sg300#sthash.HbowQPtP.dpuf