2010/10/25 Daniel-Constantin Mierla <miconda(a)gmail.com>om>:
Right, but
IMHO it would make more sense it to be a flag and not a
bflag (as the registrar server is processing the incoming transaction
rather than generating an outgoing transaction). This is, the
registrar set a flag(NATTED) before "save(location)". When retrieving
the registrations for this AoR this flag would become a bflag.
Of course this changes the current behaviour, but IMHO makes more sense.
This will make things a bit more complex, should it be there a mask of what
flags are saved as branch flags and a map of translation?
Yes, for sure my proposal would not fit very well with current design
in which a single bflag is used to set the registration as natted and
to retrieve the NAT status of a registration user. I just meant that
IMHO it makes more sense to use a flag(NATTED) before "save(location)"
rather than a bflag.
If there are
two registrations for an AoR, one of them behind NAT and
the other one with public IP, checking "isbflagset(NATTED)" in route
would retrieve 1 or 0 randomly (depending on the first branch found in
the location table). This is not consistent.
But in some deployments, you may want to keep only one registration per
user, save(location) can do that, and then you don't bother with
branch_route.
Yes, perhaps it could be better documented the risk of inspecting a
bflag (after lockup) in "normal" environments in which multiple
registrations for same AoR take place. I've seen lot of
openser/kamailio scripts failing in this point as they check the
bflag(natted) under route.
In failure route you should get the branch flags from
selected failed
branch.
But is this useful? imagine lookup("location") retrieves two
registrations (one of them behind NAT) and Kamailio receives 486 for
both branches. Which is the winning branch? AFAIK it's random so, what
is the purpose of checing bflags in failure_route?
Branch flags can be set for some other purposes, not only NAT state.
Therefore you may want to check it in failure route.
Ok, I agree that handling bflags on failure_route can make sense (not
so much on route IMHO). I just wanted to propose some constrains that
make the configuration a bit more "error-safe" :)
Regards.
--
Iñaki Baz Castillo
<ibc(a)aliax.net>