sip trunk w/o SBC

[krzysioD]

The same recurring question:
small OXE, one public IP (simple nat, with a recent SOHO router but - no vpn to sip provider)

is it possible to run a sip trunk to public sip telco provider?
anyone has tried and succeed?

If NOT then i will challenge ALU once more (just like with some hardware "will not work under OXE R8" - it works... only ALU's R'n'D don't know how to install linux on IBM). I will put some freeswitch on a4400 with static compilation - and should use "asterisk on a stick" - a SIP-aware agent on CPU, having some many codecs and options... just like i have a midnight commander on my PBX. Anyone tried, or is it just me who want to Develop this pbx into the next century?

[tot3nkopf]

I think the problem resides on provider side.
If the provider uses SBC and there is just one NAT on customer premises this should work w/o additional equipment (Asterisk).
If the provider does not uses SBC as border element by my knowledge SIP is not two times NAT capable.

Other considerations might be if the router on customer premises is ALG SIP aware (which will simulate SBC behavior).

Any other thought on this gents?