Block VoIP packs on layer 2?

By fpalio ·
I how do i block voip packets on a vlan 2 network?
The set up is as follows: the customers connects it's office overseas office their office here via E1s. These E1s are converted to IP and sent as layer 2 to customer site. The core Metro network is layer 2.


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Request for Clarification

by wfairley In reply to Clarifications

Why do you want to block the VOIP traffic? If you are experiencing issues, I recommend you configure the pipes for traffic shaping, and reserve specific minimum slices for network management, data, and voice/video. Traffic shaping will prevent a particular service (such as voip or ftp) from clogging the pipes. I recommend taking this up with your WAN engineers (including the service providers). I do not recommend blocking all VOIP packets across the pipe unless you have a WAN pipe specifically dedicated to VOIP traffic, in which case you should get your WAN engineers to fix the routing appropriately.


PS - technologies such as VTP provide mechanisms for traffic management at layer 2, and I recommend getting your network admins involved, or attend some training classes. As a minimum, I recommend Juniper Networks' free online training program which may help clarify some confusion regarding VLANS, VOIP, WAN pipes, carriers, and QoS.

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by Spitfire_Sysop In reply to Block VoIP packs on layer ...

Layer 2, in networking, strictly refers to hardware addressing called the MAC address. Lower layers are agnostic of upper layers. Anything that would identify a packet as a VoIP packet would be Protocol. A protocol exists in the transport layer known as Layer 4. In order to do the deep packet inspection required to identify that the traffic is indeed VoIP traffic you need a layer 4 filter which is commonly known as a firewall.

This has nothing to do with vLANs.

The firewall needs to be placed in to the network at the physical location that you want the VoIP traffic to stop. Example: at the originating gateway.

If you need more information you should go to a forum where people specialize in this stuff.

Go here and do a lot of reading before posting:

If you can't get the terminology straight then people won't be able to help you.

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Block VoIP packs on layer 2?

by fpalio In reply to Block VoIP packs on layer ...

thank you for your corrections. much appreciated.
OK. i pass vlan from the e1 to ip converter port all the way to the customer site. can it be done here. please help.. am new with this.


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by Manny Nkiwane In reply to Block VoIP packs on layer ...

As said by @Spitfire_Sysop, Layer 2 will not be where you will be looking to block this kind of traffic. Upper layers [thus Layer 4] is where you are looking to block, shape or manipulate your traffic.

Besides your requirement has a lot of ambiguity and you might need to explain your intentions properly for anyone to help.

I would suggest you look into having a consultant come in and help you out.
Manny Nkiwane, A+, CCNA, CCNP

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