RE: [Serusers] NAT ping and consumer router

At 04:13 PM 8/25/2004, Jesus Rodriguez wrote: Which appears like a questionnable benefit -- I mean it does not seem to make a big difference to me if the extra REGISTER load is put on SER PC or some other PC in front of it... (Not mentioning what other pain SBCs cause -- I just spent a good part of day/night reviewing a network setup in which such an SBC caused real harm.)

I objected several ideas on this mailing list, like ALGs, SBC, and other in-network NAT/SIP patches, so I should perhaps state what I consider a good idea. First it takes good NAT support in end-devices. Creating network-based patches to deal with NAT-incapable devices just creates a great amount of complexity which typically breaks other things. Make clients detect connectivity using STUN, perhaps ICE, let it send keep-alive, implement SIP stack correctly, be symmetric, etc. That's something which is achievable short-term, it is also buyer's responsibility to buy those that get it right. Long-term removing indeterminism from NATs as in IETF/behave is another important acchitectural activity. If people ask me how to make SIP/NAT stable right now, regardless of sanity, my preference is to find a good UAC and stick to it. (I have to admit I don't have a specific recommednations -- the capabilities change rapidly fimrware by firmware in a pace I can't follow.) Configure SER to help by reducing registration intervals, using a voice proxy, sending pings. -jiri