[Serusers] nathelper compability

[Jan Janak]

On 18-07-2005 19:57, Günther Starnberger wrote:
> hello,
> 
> after googling for some information about nathelper it seems that
> nathelper should be able to traverse any type of NAT (even symmetric
> ones) as long as both user agents support symmetric RTP.
> 
> is this right?

  Usually you also need RTP proxy to relay media.
  
> are there any situations where just using nathelper may not be
> sufficient? (such as transfers between an internal phone to an external
> phone or transfers between two internal phones).a

  In many situations relaying of RTP is also needed, especially if the
  phone is behind "symmetric" NATs. Traversing NATs with RTP relay can
  be done provided that one side of the call is in the public internet
  and supports symmetric RTP extensions (such as PSTN gateways, for
  example).

     Jan.