[asterisk-users] Polycom IP600 + PC share same switch port withVLAN

Lee, John (Sydney) John.Lee at compuware.com
Mon Mar 3 20:57:07 CST 2008


James, thanks for the suggestion. I am just using native vlan and I did
what you said and I believe it works :-)

interface FastEthernet2/0/2
 description VOIP VLAN 100
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,100
 switchport mode trunk
 duplex full
 speed 100

However, when I entered "spanning-tree portfast trunk", I received a
warning message which says:

"Warning: portfast should only be enabled on ports connected to a single
 host. Connecting hubs, concentrators, switches, bridges, etc... to this
 interface  when portfast is enabled, can cause temporary bridging
loops.
 Use with CAUTION"

As the polycom phone is acting like a switch, I decided not to put that
option in.

***Also, can I just confirm that with the current QOS (quality of
service) settings on the polycom phones, the phone should have priority
over the PC?

Thanks in advance.





> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-
> bounces at lists.digium.com] On Behalf Of James Sneeringer
> Sent: Saturday, 1 March 2008 9:57 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [asterisk-users] Polycom IP600 + PC share same switch
port
> withVLAN
> 
> As far as I can tell, with Polycom phones you cannot do what you're
> asking (which is for the PC and the phone to be in the same VLAN while
> the PC is connected to the phone). I don't know how they handle it
> when the voice frames are untagged, but they definitely won't pass
> tagged voice frames to the PC port:
> 
>
http://knowledgebase.polycom.com/KanisaPlatform/Publishing/616/12526_f.S
AL
> _PUBLIC_1_2.html
> 
> Your switch port is configured for untagged frames on a single VLAN
> (that's what "access" mode is). Polycom phones need voice and data to
> be on separate VLANs in order for you to use the PC port. Since
> Polycom phones apparently don't support the Cisco Voice VLAN feature,
> you need to configure the port as a trunk port, which will allow you
> to send multiple VLANs to the phone. The phone will take frames tagged
> for your designated voice VLAN, and will pass the rest on to the PC
> port. For example:
> 
> interface FastEthernet2/0/1
>  switchport trunk encapsulation dot1q
>  switchport trunk native vlan XXX
>  switchport trunk allowed vlan XXX,100
>  switchport mode trunk
>  spanning-tree portfast trunk
> 
> Replace XXX with whatever your PC VLAN is. Setting XXX as the native
> VLAN for this port will cause frames in that VLAN to be untagged for
> that port, which is what your PC probably expects. If it happens to be
> 1, then it's the native VLAN by default. The last command may or may
> not be available, depending on your version of IOS. If it isn't,
> portfast just won't work and you're just stuck with STP negotiation
> anytime the port bounces.
> 
> -James
> 



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