Managed/Unmanaged SIP Trunks

[libellis]

For a CUCM system:

We have the option to order SIP trunks in one of two ways:

1) Local access would be via a T1 that ties into the SIP Provider's MPLS backbone, but the T1 would not be part of the Provider's managed network and any issues would have to be worked out with the local Carrier that provides the T1. The T1 circuit would connect directly to the Cisco Gateway/Router (via VWIC) in the CUCM system.

2) The SIP Provider can install a completely managed network including responsibility for the local access T1 and the router to which it terminates. In this case, the hand-off would be a connection from their router to the network that CUCM is on. The Session Border Controller (CUBE)would still run on the CUCM associated Gateway/Router and not on the SIP Provider's edge router.

We know what the tradeoffs between these two options are, but the question we have is if there is something about either of these options that would make one more preferable than the other with regard to real world CUCM setup/complications and problem resolution. Is the answer as simple as "if you can afford the fully managed option, then go for it"?

 

[vnetmanager]

I manage a network of hospitals and we are preparing to move to SIP trunks as well. Our decision to go fully managed is based on reliability of the local carrier to respond to an outage in a timely manner. Our experience is that, while their own PRI T1s are reliable, leased circuits are not held as a priority so if there were an outage we would probably not get the response we want. Also, we decided to provide the CUBE as owned equipment instead of just connecting to the SIP provider's because of the size of our network. We will end up with about 10,000 DID numbers coming in to 2 hubs and then distrbuting over our network.
That's it from my little world.

JB

 

[libellis]

We have a much smaller system, but managed has advantages. I just wanted to be sure that from a CUCM installation and configuration perspective that there wasn't some important difference (other than direct T1 connection via VWIC in the CUCM system gateway/router vs network connection to the Carrier's router). We plan to run CUBE on the CUCM gateway/router. Session Border Control will not be provided on the Carrier's router.