I am looking to get a Single SIP trunk to break out into multiple 924s to support FXS dial tone to the customer. I purchased a Netvanta 3448 to achieve this but not entirely sure on how I should have it setup. As I have only done a single 9xx series deployment. I have attached what I normally would do for a single trunk to 9xx series IAD for reference. Here is a diagram of what my setup is to look like
The 3448 part is easy. Put the connections to the TA924 ethernet ports in a /29 or shorter subnet and route to them. Don't NAT within the 3448. Four trunks on the Broadworks, each with the appropriate users of the 924 terminating the FXSs. You may need to tweak some things if you want to keep the media local for extension calls between different TA924s. Kind of depends on your SBC.
Is there a way to use the same SIP trunk, 1 Pilot user, for all 4 924's? The end goal is to have 1 SIP trunk feeding 80+ POTS lines buts their concurrent call ratio is small.
If each TA924 has different unique extensions on FXS ports, no. The Broadworks won't be able to identify the correct device on which to land the call. A really ugly hack would be to build local SIP trunks and grouped trunks on each TA924 and hairpin the call to the correct one. This becomes a real nightmare with adds, moves, and changes as well as introducing points of failure in series as well as a really fun thing (NOT!) to troubleshoot. Don't do it. Use four trunks.
If the TA900s all feed PRIs to a common PBX as opposed to individual analog phones with unique extensions, then you can use the "Enterprise trunk" feature in Broadworks to group the devices together. In this scenario, a call to any given DID may land on any of the TA900s, but they all feed a common PBX which will perform the final routing to the individual phone.
I would assume I would just need to route the extension to each 924
But that's done by listing the DIDs of the users under the trunk, so you still need four trunks as each 924 will have a unique registration (or unregistered IP).