[Users] nat flag and branch routes

Daniel-Constantin Mierla daniel at voice-system.ro
Wed Aug 31 12:34:50 CEST 2005

On 08/31/05 12:59, Bogdan-Andrei Iancu wrote:

> Hi,
> it works, but is not save since you can not be 100% that dst_uri 
> presence is strictly related to NAT traversal. It's also used by RR 
> module to force routing after loose_route; and by dispatcher for the 
> same reasons.....

if you do not call other function that alter the r-uri except 
lookup(location) as I said, I do not see why is not 100% sure that the 
user is behind the nat. When loose_route() is used, lookup(location) 
should not be used, I see no good reason.  dispatcher is for load 
balancing and it is usually in front of registrar. In this 
circumstances, I would say that the situations to have many settings of 
dst_uri is very less probable.


> I see here two ways of approaching this issue:
>    - to have per-branch flags also before transaction creation; will 
> be a new param to append_branch (8 in total :-/), but this flags will 
> not be accessible from script; only in branch route;
>    - use something else than flags for NAT marking (something already 
> present in all branch stages): nathelper, when builds the received URI 
> (which will become dst_uri) will append a "nat=yes" parameter; this 
> parameter will be easyly identify in branch route and NAT traversal 
> may be activated....

> any comments or new options are welcomed.......
> regards,
> bogdan
> Daniel-Constantin Mierla wrote:
>> I would say yes, if you do not call other functions that alter the 
>> r-uri/dst_uri, except lookup("location").
>> Daniel
>> On 08/30/05 19:43, Richard Z wrote:
>>> Just a thought... is it possible to ingore the nat flag and just 
>>> rely on the existence of dst_uri to indicate a NATed UA?
>>> On 8/29/05, *Klaus Darilion* < klaus.mailinglists at pernau.at 
>>> <mailto:klaus.mailinglists at pernau.at>> wrote:
>>>     Ho Bodgan!
>>>     To use branch routes for branch-only NAT traversal also the 
>>> nathelper
>>>     and mediaproxy functions must be adopted to work in branch routes.
>>>     regards
>>>     klaus
>>>     Bogdan-Andrei Iancu wrote:
>>>     > Hi,
>>>     >
>>>     > indeed, prior branch_route, there is only one set of flags
>>>     shared by all
>>>     > branched - that's still unchanged.
>>>     >
>>>     > regards,
>>>     > bogdan
>>>     > 

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