[Asterisk-Users] * and Verisign SIP-7 service

[Kevin P. Fleming]

Matthew Crocker wrote:
> 
> I know the AS5400 has STP functionality and I can terminate A-links from 
> the Verizon STP.   What would handle the ISUP messages?  Can Asterisk 
> handle that part of the transaction?

If the AS5400 is doing STP, then it would have to handle ISUP itself.

>  I'm a CLEC so I'm planning on getting NPA-NXX thousand blocks from 8 
> rate centers in the LATA.  I'll need to handle IMT trunks from the 
> Verizon access tandem and some Verizon end-offices.  For the amount of 
> traffic I'm going to be looking at the SIP-7 stuff would probably be 
> cheaper than direct SS7 links.

Cheaper and easier to manage as well, and far more expandable.

>  From my understanding the originating switch will send an ISUP message 
> to my SSP using my point-code over the SS7 network.  The AS5400 would 
> get the ISUP message and needs to send it somewhere to figure out what 
> to do.  The AS5400 would use MGCP (I think) to talk to a softswitch 
> (Asterisk??).  If Asterisk can do it all that would be amazing!

No, Asterisk cannot control an MGCP gateway at this time. If the AS5400 
is in MGCP mode, it will be expecting a softswitch to control it, and it 
will likely not be able to do STP/ISUP or any other control protocols at 
the same time. In MGCP mode, it's a fairly "dumb" PSTN<->packet voice 
translator (same is true for any MGCP-controlled media gateway, the 
controlling softswitch has all the smarts).

I don't know what the capabilities of the AS5400 are, but it's possible 
that it could originate/terminate SIP to an Asterisk server, while doing 
STP/ISUP on the PSTN side. Still, that would be more expensive than 
using an IP-based SS7 service (whether that's Verisign's SIP-7 service 
or SIGTRAN from another SS7 network), because of all the SS7 links required.

Your point about multi-LATA expansion also hits it right on the head: 
Verisign likely already has an SS7 presence in every LATA you want to be 
in, so if you use their service you get access to all of that by just 
making a phone call (and signing some magic pieces of paper with numbers 
on them <G>).