[Users] SIP vz IAX...

Hello Users..... I'm in Dilemma with the performance on SIP and IAX.... Can any one help ... 1) Difference between the SIP and IAX... which one is Best... in VOIP service I'm using only SIP protocol for my VOIP in OpenSER... And Also I using Asterisk in SIP.... we can Communicate the SIP and IAX by below scenario SIP (UA) --------> OPENSER -----> ASTERISK --------> IAX (UA)....... this I can do... IAX -----------> OPENSER -----> ASTERISK ---------> SIP/IAX. But main problem is ... Suppose IAX ------> ASTERISK-----------> openSER ------------> SIP / IAX ... How ? Help me this.... forgive me in English.... :P -- Thanks and Regards Ravi Prakash Sunkara ravi.sunkara(a)hyperion-tech.com M:+91 9985077535 O:+91 40 23114549 F:+91 40 40208727 ravi.sunkara(a)hyperion-tech.com www.hyperion-tech.com