30 Jun
2004
30 Jun
'04
1:52 a.m.
Thanks for your feedback Klaus,
Klaus Darilion wrote:
1. How will you do the load balancing? Do the several
ser servers have a
single IP address? As the clients are behind NAT, the NAT traversal
always has to be done by the proxy which acceptet the registration of
the client (only this IP address is allowed to traverse the NAT in case
of symmetric NATs).
The router in my diagram will have "Stciky IP" which will maintain the
udp connection between a UA, and the first ser front end it hits.
Furthermore you have to ensure that all messages of a
transaction
traverse the same proxy.
In my test environment I was rewriting the URI on the front and back end
box with a hard coded host name, but this will get more complicated when
I add more than one front end boxes. One option that I have been mulling
is to possibly use the textops modules to rewrite the URI to the origin
address of the recieved SIP message, this should make all messsages that
the backend replys to will go to the originating front end ser. Does
this make sense? Failing the textops module, I think I can run sed (or
similar) on the sip message. Keeping the message rewriting inside the
ser instance seems preferable to me.
Another point is that only the SIP proxy which
acceptet the registration
knows about the current location of a UA, except you use the t_replicate
feature.
I understand now that I will need to have a location (persistent or not)
on the front end servers. I imagine it should not be a problem to use
t_replicate() across all my front end servers, but will this mean that
all ser front end servers will attempt to send udp ping packets to
natted clients?
Thanks!
-Jev