Switching to SIP Trunks

[ClaytonR]

Hello,

We are moving offices, and are moving to SIP Trunks instead of PRI. I know I need to purchase SIP Trunk Licenses. I have been told that I need a MBG and SIP channel Proxy licenses. What are these additional items needed for?

 

[DoubleUT]

The MBG is mainly used for Mid-Call features. It might also be possible that the provider that you are going to use is only tested and certified with the use of an MBG. I would advise to use one.

 

[ClaytonR]

ok but if I am just getting SIP Trunks, why do I need the SIP channel Proxy licenses?

 

[jpruder]

First I would say that the preferred method of providing sip trunking is through the MBG proxy.

The MBG also would easily extend to support remote teleworkers with the purchase of a license.

I have no idea of how many trunks you are needing, but I would add that you also look at using an Adtran 908e to connect to the sip providered and convert to PRI to the Mitel. This would need a cost analysis but likely if at 23 cheaper.

 

[bribob]

Clayton,

Think of the MBG as an anchor point for all the SIP and RTP packets traveling between your voice network and SIP provider. The SIP trunk would terminate at the MBG, on the WAN interface if the MBG is in Server-gateway mode or on the LAN interface if you wanted to play dangerous and deploy in Server-only mode and NAT to it.

Without an MBG (SIP proxy), your voice network will have to be able to route to the SIP provider. This may introduce a security hole in your network.

Having a single point to proxy audio and SIP control packets is nice and convenient. Mitel knows this, and wants you to want it, and wants you to pay for it.


-b

 

[jpruder]

I agree with bribob, he is dead on with how Mitel wants to see things. My only concern is the cost. On a new install that was sip, I'd go the golden path. If I was changing from PRI, I'd be hard pressed not to consider the 908e model. Which one would depend on your compression requirements.

They are not hard to program, have some in the field providing shared pri via sip as backup dialtone and others doing T38 faxing. It's a nice piece of equipment to have in the arsenal IMHO.