[Serusers] using SER as a frontend to asterisk SIP/PSTN gateways?

[Roy Sigurd Karlsbakk]

hi

I've been told to setup a 48-PRI SIP/PSTN gateway system, and want to 
do this as follows:

1 SER server proxying all incoming SIP connections
12 asterisk servers with 4 E1 PRIs each doing the actual SIP/PSTN 
gatewaying
1 database server for number routing, call details and authentication 
info

Questions:
  - How can I setup SER to forward up to 120 calls per asterisk node 
before switching to another one? does SER keep a list of open RTP 
connections to the box forwarded to?
  - Can multiple SER boxes be used for failover or load balancing?

thanks

roy