M. Ranganathan wrote: > You can connect enterprises using only proxy servers. You have to open > up ports in your firewall and administer firewall rules and dial > plans. > > I leave you with that point of view. Please feel free to explore.
There is one important aspect of B2BUA vs. SIP Proxy that you guys have not mentioned yet in this discussion. I am talking about accurate accounting. It is not possible to do accurate accounting with SIP Proxy, in the situation when either traffic source of destination cannot be trusted to behave correctly and not be trying to abuse the service purposely or by mistake. This is the case with all ITSPs out there - they buy minutes from one source and sell them to another at a higher price, living off the difference. Both sides in this configuration are potentially interested in skewing accounting - the party that sends a traffic would gain if it can use more minutes that it has been accounted for, while the party that receives traffic would gain if it can bill for more minutes that have been actually consumed. Yes, I know some proxies can generate accounting, but there are too many loopholes in SIP to abuse accounting generated by the proxy. All that accounting functionality relies on the fact that endpoints behave strictly to the RFC and it's really easy for anybody with at least moderate RFC3261 knowledge to bypass. So that ITSP which uses SIP Proxy for this purpose in the situation described above puts himself open for intentional or unintentional abuse. Another reason why ITSPs might want to use B2BUA is to hide traffic destination from its clients to prevent them from cutting direct dial. Again, this is not possible with pure SIP Proxy. There was lengthy discussion on this topic some time ago here. Regards, -- Maksym Sobolyev Sippy Software, Inc. Internet Telephony (VoIP) Experts T/F: +1-646-651-1110 Web: http://www.sippysoft.com MSN: sa...@sippysoft.com Skype: SippySoft _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
