Personally, I think it would be much easier, and better to use dedicated hardware to terminate the A-link, MTP1 & 2 and pass everything to Asterisk via IP. Something like chan_sigtran. The standards for SS7 over IP are a moving target but it is IMHO where Asterisk should be headed. Traditional SS7 (packet over 56k DS0) is a dinosaur and will be replaced over time. I like the design behind the ss7box.com. Companies like Verisign are already doing SIP-7 and SS7 over IP. If Asterisk could connect directly to their service a provider wouldn't need an SS7 Gateway. If Asterisk is designed to use a separate hardware box for MTP1 & 2 it would allow a lot of flexibility. The SS7 gateway could be another Asterisk box which is purpose built to handle the SS7 and hand it off to a call processing (softswitch) Asterisk server. Something like [ss7] -> Asterisk --- [sigtran/mgcp] ---> Asterisk. In my perfect world I would have something like: SS7 --- [2 x A link ] ---> [SS7 Gateway] ---- [IP] ----> Asterisk PSTN --- [IMT] ----> [Media Gateway] --- [ IP ] ----> Asterisk [ IP ] ---> [Media Gateway] --- [PRI] --> [Customer PBX] [ IP ] ---> Customer SIP Phone For Media Gateway I would use Cisco 5350s colo'ed into the Verizon COs. Each 5350 would terminate IMTs from the local Verizon End Offices. Ideally, each 5350 cluster would have their own SS7 point- code and be classified as an End Office. Verizon would be responsible for getting their calls to me at my EO. If they don't terminate at the EO they can hand it off to my 'tandem' which is just another 5350 plugged into the Access Tandem. I would use Cisco AS5350s because one of my requirements is dialup ISP RAS service. Any other media gateway that can handle v.92 (PPP) and g.711/g.729 could be a replacement for the 5350s On top of all this the SS7, ISUP, TCAP has to be certified and pass testing with Verizon to make any sense. My requirements might be different, I'm a facilities based DLEC. I already have dark fiber/GigE and SCOPE colo bays in the Verizon COs I'm interested in. I have IPDLCs that can terminate POTS from customers into VoIP (SIP/MGCP). I have 4.6mbps 2xSHDSL loops to customers where I can hang a media gateway (CAC Adit ??) for derived PRI delivery. I have everything but a switch, and I'm pouring over quotes now trying to figure out a switch budget -Matt On May 13, 2005, at 8:58 AM, Angel Diaz wrote: > Lets do this: > 1- Is it possible to develope on GLP ? > 2- In case the answer is "NO"; What can we do then? > 3- In case the answer is "YES"; We have to decide: > - Create the SS7 stack as a module in the asterisk ? > - Create as an external library ? > - etc, etc. > > What user part of the SS7 the people need; ISUP, TCAP, TUP, etc? > If we take statistics, about what the people ask for ... it is > ISUP, because > they need to interconect to the PSTN, Cellular Network or other ... > > > > _______________________________________________ > Asterisk-SS7 mailing list > Asterisk-SS7@xxxxxxxxxxxxxxxx > http://lists.digium.com/mailman/listinfo/asterisk-ss7 > -- Matthew S. Crocker Vice President Crocker Communications, Inc. Internet Division PO BOX 710 Greenfield, MA 01302-0710 http://www.crocker.com
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