[asterisk-ss7] Large SS7 installation (96 E1s)

[Antoine Megalla]

Hi,
(Sorry about the missing subject line in the last email, and the double submit)
 
I have a huge Asterisk SS7 project, and I am wondering about the best approach/architecture to satisfy the client's requirements.
 
The client has 96 E1s connected to a PSTN provider, and he needs a prepaid application.
The 96 E1s are all SS7 ITU flavor.
Although the client currently has 4 signaling links for the whole 96 E1s, he claims that he can obtain any number of signaling links (linksets) I need.
 
I have implemented several SS7 solutions before, all based on Asterisk-1.2.24, chan_ss7-1.0.9 and using Digium TE410P cards, but nothing of that magnitude, so I am wondering if anyone has an experience he/she can share for the best approach to this installation.
 
The lines will not 100% utilized all the time of course, but at peek times, it is supposed to go up to 90% utilization.
 
I think the architecture for this project should look like the following:
Using 12  separate 1U servers. 
Each server has a quad core Xeon processor, and 4 Gigs of RAM
Using 1 Sangoma A108 eight port interface card in each server (since Digium does not provide more that 4 span cards).
Each server will handle one linkset (needing 12 signaling links from the operator)
Asterisk-1.2.24
Chan_ss7-1.0.9
Centos 5
 
This is the architecture based on my past experience, and I am not sure if it will handle the load or if I need to change the architecture or add more CPU power.
 
There many unknowns to me:
For example I don't know if I can put 16 E1s per server?
Should I put the prepaid application on the same Asterisk SS7 box, or should simply convert from SS7 to SIP on one box, and then forward the SIP call to another Asterisk box where the application is hosted?
How stable is the Asterisk 1.2 chan_ss7 1.0.9 combination under for 8 E1s per server?
Does the Sangoma driver has any problems with such setup?
I have never tried libSS7, so I don't know if it scales better, is it more stable, or is there any added benefits of using libSS7 over chan_ss7?
 
I know there are people who are much more experienced on this mailing list, so please if you have any advise or recommendations I will appreciate the help.
 
Thank you and best regards,
 
Antoine Megalla.