Asterisk Custom work

Customer will dial on our inbound DID number 123456789. Customer can call us using asterisk SIP extension, mobile or landline number. As soon as call will come to our server. it will match caller ID stored in the database. if caller ID is not matched then it will play goodbye message and call will hangup but if caller ID is matched then server preform following. Our system will ask user to enter destination phone number along with coutnry code 91-987654321 our system will get that number and it will add a prefix of 192 and it will dial that number 192-91-987654321 using GSM SIP Gateway 1 on available SIP account. for example SIP1-GW1 is busy then system will automatically dial number 192-91-987654321 using SIP2-GW1. as soon as number is dialed using SIP2-GW1 system will store its SIM number 456 (we can store all SIM number in database)and then after 10 sec system will dialed that SIM number 456 using any avalible SIP account on GSM SIP Gateway 2. after 30 min call will ba hangup automatically. *********************************************** GSM SIP Gateway 1 -------------------------------------------------------------- SIP1-GW1 (SIM number 123) SIP2-GW1 (SIM number 456) SIP3-GW1 (SIM number 789) ************************************************** GSM SIP Gateway 2 ---------------------------------------------------------------- SIP1-GW2 SIP2-GW2 SIP3-GW2