[Serusers] Access control on PSTN gateways

[Michael Graff]

We have a group of people who run their own SIP servers (some are
SER, some are not) and we are going to be sharing a PSTN gateway (Cisco
box).

I need to rewrite the identities for the users of our gateway into
something that can be presented to the PSTN gateway for billing
purposes.  We don't want to do that mapping on the gateway itself, for
various reasons.

How do people handle this situation?  Is it wise to put all functionality
for user handling and incoming call handling and forwarding to another
place in the same SER server?

--Michael