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New Member

Initial VoIP configuration

I am trying to generate a VoIP configuration for a customer. The customer already has a 3825 ISR router on their Border facing the Internet.

I watched a Cisco Web presentation this morning which did indicate that the 3825 router was a Voice capable router (hence ISR). I used the Cisco Partner Helpline earlier and basically configured the 3825 to figure out the pieces parts that I would need to provide the demo VoIP config.

I have several more design questions however. I had indicated earlier that the 3825 router was the Border Router to the Internet. Behind it are two Firewalls in series to provide a DMZ. Then after the 2nd (Inside) Firewall is the production network. The core of the production network is a 4506 Switch with a Sup II+ blade for L3 services. This is a smaller network, and this switch works well for the Core.

In this customer's VoIP demo, we want to move forward with only 5 phones initially. I have a PoE blade in one of the slots in the 4506 Core switch. Can i plug these IP phones into the PoE ports on the blade in the 4506 switch and have them work? Is there any special requirement with respect to the IOS running on the 4506 Core Switch?

Also I am curious what ports I would have to allow inbound across both of the Firewalls from the 3825 router?

If it is an option, I can attach a Network diagram to help make all this clear.

Thanks for any advice here.

Cisco Employee

Re: Initial VoIP configuration


For your first question on the PoE module, it is really depend on what type of module you are going to get. Every module has its own minimum IOS requirement. As long as you are meeting the requirement, you will be fine.

Also, if your are using your edge (Internet) router as your voice gateway, please see the following document on the port usage for voice traffic

Hence, I am assuming your are going to demo Cisco Unified CallManager 6.x.



New Member

Re: Initial VoIP configuration


We had used the Dynamic Configuration Tool and Cisco Part Number FL-CCME-25 (Communications Manager Express) had been selected. I am not sure what version it is, but i know we had picked the latest one.

That document you sent will be very helpful. That is a huge amount of ports to have open!


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