25 Jan
2003
25 Jan
'03
10:57 a.m.
Jiri Kuthan writes:
technique: UPnP
requirements: NATs and phones with UPnP support; Messenger and
snom are known to support UPnP; there is linux
support for it
but how many nat boxes support upnp? last time i looked at ms upnp
page, the list was very short.
technique: ALG
requirements: SIP-capable NAT (like Intertex or Cisco/PIX)
i like this one. cisco ios nat that is built in every cisco router
now has sip alg. you must have very recent ios version though.
technique: STUN
requirements: STUN-enabled phone (like k-phone, snom)
limitations: doesn't work over symmetric NATs (words-of-mouth propaganda
has been telling me that many residential NATs are fortunately
not symmetric, but I don't know how objective this information
really is)
we have tried kphone's stun in all mojor dsl providers in finland that
nat their customers and haven't had problems with any. in some cases
you have to run stund in your outbound proxy and not in some other ip
address.
-- juha