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New Member

Classifying VoIP bearer flows

Is there a switching product that can be configured to classify untagged ethernet (ip) frames arriving at a switch port into two categories: VoIP bearer streams and non-VoIP bearer streams, such that the VoIP stream gets mapped to a specific VLAN (with specific 802.p value) and the non-VoIP streams remain untagged, and both streams are forwarded to a single egress port.

  • Other Network Infrastructure Subjects
3 REPLIES

Re: Classifying VoIP bearer flows

Hi,

I'm not sure if I understand your question completely. Do you mean that the switch should recognize the VoIP traffic itself? How could it be done - based on which frame field?

Cat2950 can recognize VoiP frames tagged with 802.1p tag by IP phone, e.g.

See http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2950/12113ea1/2950scg/swvoip.htm

and

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2950/12113ea1/2950scg/swqos.htm#1083017

for details.

Regards,

Milan

New Member

Re: Classifying VoIP bearer flows

To clarify, can the switch identify the VoIP flow by inspecting the IP header in an untagged Ethernet, IP encapsulated frame on on receipt at the ingress port, and then insert a VLAN tag when transmited on egress port. Obviously this assumes some layer 3 capability in the switch.

Re: Classifying VoIP bearer flows

Hi,

could you be a little more specific about your idea of "inspecting the IP header in an untagged Ethernet"?

AFAIK, Cat2950 and 3550 enable to use IP access lists (IP source address, e.g.) to recognize some traffic, e.g. You can change the CoS and DSCP priorities of this flow on the egress.

See the URLs I sent you in the previous response.

But you are not able to tag it with another VLAN ID.

Regards,

Milan

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