Switches, Hubs, and Modems
Showing results for 
Search instead for 
Did you mean: 

Multiple VLANS same port VOIP

Occasional Visitor

Multiple VLANS same port VOIP

Purchased a 5406zl and need help configuring the switch to support 2 seperate VLANS on the same port. Our IP phones piggy back to the PC eliminating the need for a second network drop. Is it possible to segment the phone and the PC to 2 seperate VLANS? Any other suggestions on how to get the best quality from the phones since they will be sharing the bandwidth? Thanks in advance.
Mohieddin Kharnoub
Honored Contributor

Re: Multiple VLANS same port VOIP


Usually, the PC or the Phone should be connected to untagged port to the relevant Vlan , so if we want the client to be in Vlan1 then his switch port should untagged to Vlan1, and similar thing to the IP Phone.

Using the 802.1x we can have a Dynamic Vlan assignment based on the Authentication by RADIUS server that passes the desired Vlan.

So if your switch port connected to an IP Phone and the user connects to the extra Ethernet port on the IP Phone, i believe that we can add the Phones's MAC to the RADIUS server with Vlan assignment to (say Vlan2), and if the user authenticates when he connects against the RADIUS server he can get different Vlan assignment.

With some Avaya IP Phones you can configure the Vlan ID, and it will tag the traffic with this VID, but in the switch side, i haven't test if the port can be tagged.

If it can be tagged, then you can untag the same port to be used by the user also.

Good Luck !!!
Science for Everyone
Trusted Contributor

Re: Multiple VLANS same port VOIP

You might set the port of the managed switch to "untagged" for the VLAN the PC is supposed to be, and "tagged" for the VOIP device, if this supports IEEE 802.1Q standard. I assume that you use a small flat switch/hub or some equivalent device (WiFi access point, maybe) to connect the PC _AND_ the IP phone to one port of the managed switch. This device does not need to support 802.1Q for the things to work OK for you, but is does support this standard you should set this device, too, according to your requirements.

On the managed switches, though, you should use prioritization, so that the VOIP VLAN frames are transmitted with higher priority through your switching topology than normal data frames (i.e. frames coming from the PCs). If I remember well, there are a lot of threads on this very "switches, hubs, modems" forum subject that may clear the air for you regarding prioritization - so you could consult these ones, or some other documentation on the subject.