14 Sep
2016
14 Sep
'16
10:11 a.m.
Hi,
I am struggling to figure out variable scope in branches and branch_failure_routes. Is
there a way to store a variable in a branch route so that I can then read it from the
branch failure route if that branch fails? Also does writing $ru in branch_failure_route
append a branch?
For example I have multiple SIP devices registered to Kamailio on the same account
credentials. The devices are behind same NAT, so same public IP. Some devices have SRTP
required and some cannot use SRTP at all, Kamailio does not know in advance of the call
whether the call will use SRTP or RTP.
When I send a call to that user Kamailio correctly parallel forks to all the registered
devices. I use rtpengine offer to send SDP with RTP/SAVP in the initial invites.
If one of the devices sends a 488 due to not being able to handle the RTP/SAVP I then want
to run rtpengine_offer with RTP/AVP and send another invite to the same device.
In the branch failure route I seem to have to read the current $ru and then write it back
into $ru before calling t_relay() or I get
Sep 14 14:56:06 registrar-secure /usr/sbin/kamailio[10168]: ERROR: tm [t_fwd.c:1771]:
t_forward_nonack(): ERROR: t_forward_nonack: no branches for forwarding
This code seems to work, but it feels like I’m doing something very wrong…. in particular
$avp(triedrtpout) is set for the transaction, I should be setting it separately for each
branch.
event_route[tm:branch-failure:SRTP] { # Handle failure response
xlog("L_INFO", "Handling $T_reply_code response to $rm to ru:
<$ru> and du: $du\n");
if(t_check_status("488") && is_method("INVITE")) {
if ($avp(triedsrtpout)==1) {
# set $ru seems to create a new branch ... even when we set it to
its current value.
# we want to generate a new SIP INVITE to the same AOR but with
different SDP
$avp(buffer)=$ru;
$ru=$avp(buffer);
xlog("L_INFO","488 caught. Resending to
$ru");
# try with unencrypted RTP/AVP
rtpengine_delete();
rtpengine_offer("to-tag trust-address replace-origin
replace-session-connection ICE=force RTP/AVP");
if (!t_relay()) {
sl_reply_error();
}
}
}
}
I am using kamailio 4.2 debian package for this registrar.
Sorry for the rambling question … I don’t understand enough to write the short version!
Paul
14 Sep
14 Sep
10:36 a.m.
Hello,
there is no variable that is stored in the scope of the branch. What you
can use is a hash table and compose the key from callid and branch index
variables with expires that is same as transaction lifetime (max
retransmission timeout).
And indeed you need to 'touch' the r-uri in order to signal to kamailio
that you have a new destination and want to create a new branch. It may
work to just use append_branch(), otherwise reassigning $ru to itself
should do it.
Cheers,
Daniel
On 14/09/16 16:11, Paul Smith wrote:
Hi,
I am struggling to figure out variable scope in branches and
branch_failure_routes. Is there a way to store a variable in a branch
route so that I can then read it from the branch failure route if that
branch fails? Also does writing $ru in branch_failure_route append a
branch?
For example I have multiple SIP devices registered to Kamailio on the
same account credentials. The devices are behind same NAT, so same
public IP. Some devices have SRTP required and some cannot use SRTP
at all, Kamailio does not know in advance of the call whether the call
will use SRTP or RTP.
When I send a call to that user Kamailio correctly parallel forks to
all the registered devices. I use rtpengine offer to send SDP with
RTP/SAVP in the initial invites.
If one of the devices sends a 488 due to not being able to handle the
RTP/SAVP I then want to run rtpengine_offer with RTP/AVP and send
another invite to the same device.
In the branch failure route I seem to have to read the current $ru and
then write it back into $ru before calling t_relay() or I get
Sep 14 14:56:06 registrar-secure /usr/sbin/kamailio[10168]: ERROR: tm
[t_fwd.c:1771]: t_forward_nonack(): ERROR: t_forward_nonack: no
branches for forwarding
This code seems to work, but it feels like I’m doing something very
wrong…. in particular $avp(triedrtpout) is set for the transaction, I
should be setting it separately for each branch.
event_route[tm:branch-failure:SRTP] { # Handle failure response
xlog("L_INFO", "Handling $T_reply_code response to $rm to
ru: <$ru> and du: $du\n");
if(t_check_status("488") && is_method("INVITE"))
{
if ($avp(triedsrtpout)==1) {
# set $ru seems to create a new branch ...
even when we set it to its current value.
# we want to generate a new SIP INVITE to
the same AOR but with different SDP
$avp(buffer)=$ru;
$ru=$avp(buffer);
xlog("L_INFO","488 caught. Resending to
$ru");
# try with unencrypted RTP/AVP
rtpengine_delete();
rtpengine_offer("to-tag trust-address
replace-origin replace-session-connection ICE=force RTP/AVP");
if (!t_relay()) {
sl_reply_error();
}
}
}
}
I am using kamailio 4.2 debian package for this registrar.
Sorry for the rambling question … I don’t understand enough to write
the short version!
Paul
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
--
Daniel-Constantin Mierla
http://www.asipto.com - http://www.kamailio.org
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
1:53 p.m.
Makes sense. I thought I was missing something. Hash table will work well.
Thanks Daniel.
On 14 Sep 2016, at 15:36, Daniel-Constantin Mierla
<miconda(a)gmail.com> wrote:
Hello,
there is no variable that is stored in the scope of the branch. What you can use is a
hash table and compose the key from callid and branch index variables with expires that is
same as transaction lifetime (max retransmission timeout).
And indeed you need to 'touch' the r-uri in order to signal to kamailio that you
have a new destination and want to create a new branch. It may work to just use
append_branch(), otherwise reassigning $ru to itself should do it.
Cheers,
Daniel
On 14/09/16 16:11, Paul Smith wrote:
Hi,
I am struggling to figure out variable scope in branches and branch_failure_routes. Is
there a way to store a variable in a branch route so that I can then read it from the
branch failure route if that branch fails? Also does writing $ru in branch_failure_route
append a branch?
For example I have multiple SIP devices registered to Kamailio on the same account
credentials. The devices are behind same NAT, so same public IP. Some devices have SRTP
required and some cannot use SRTP at all, Kamailio does not know in advance of the call
whether the call will use SRTP or RTP.
When I send a call to that user Kamailio correctly parallel forks to all the registered
devices. I use rtpengine offer to send SDP with RTP/SAVP in the initial invites.
If one of the devices sends a 488 due to not being able to handle the RTP/SAVP I then
want to run rtpengine_offer with RTP/AVP and send another invite to the same device.
In the branch failure route I seem to have to read the current $ru and then write it back
into $ru before calling t_relay() or I get
Sep 14 14:56:06 registrar-secure /usr/sbin/kamailio[10168]: ERROR: tm [t_fwd.c:1771]:
t_forward_nonack(): ERROR: t_forward_nonack: no branches for forwarding
This code seems to work, but it feels like I’m doing something very wrong…. in particular
$avp(triedrtpout) is set for the transaction, I should be setting it separately for each
branch.
event_route[tm:branch-failure:SRTP] { # Handle failure response
xlog("L_INFO", "Handling $T_reply_code response to $rm to ru:
<$ru> and du: $du\n");
if(t_check_status("488") && is_method("INVITE")) {
if ($avp(triedsrtpout)==1) {
# set $ru seems to create a new branch ... even when we set it to
its current value.
# we want to generate a new SIP INVITE to the same AOR but with
different SDP
$avp(buffer)=$ru;
$ru=$avp(buffer);
xlog("L_INFO","488 caught. Resending to
$ru");
# try with unencrypted RTP/AVP
rtpengine_delete();
rtpengine_offer("to-tag trust-address replace-origin
replace-session-connection ICE=force RTP/AVP");
if (!t_relay()) {
sl_reply_error();
}
}
}
}
I am using kamailio 4.2 debian package for this registrar.
Sorry for the rambling question … I don’t understand enough to write the short version!
Paul
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org <mailto:sr-users@lists.sip-router.org>
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
<http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users>
--
Daniel-Constantin Mierla
http://www.asipto.com <http://www.asipto.com/> - http://www.kamailio.org
<http://www.kamailio.org/>
http://twitter.com/#!/miconda <http://twitter.com/#!/miconda> -
http://www.linkedin.com/in/miconda
<http://www.linkedin.com/in/miconda>_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users 
3 p.m.
On Wednesday, September 14, 2016 3:11:08 PM CDT Paul Smith wrote:
Hi,
I am struggling to figure out variable scope in branches and
branch_failure_routes. Is there a way to store a variable in a branch
route so that I can then read it from the branch failure route if that
branch fails? Also does writing $ru in branch_failure_route append a
branch?
For example I have multiple SIP devices registered to Kamailio on the same
account credentials. The devices are behind same NAT, so same public IP.
Some devices have SRTP required and some cannot use SRTP at all, Kamailio
does not know in advance of the call whether the call will use SRTP or RTP.
When I send a call to that user Kamailio correctly parallel forks to all the
registered devices. I use rtpengine offer to send SDP with RTP/SAVP in the
initial invites.
If one of the devices sends a 488 due to not being able to handle the
RTP/SAVP I then want to run rtpengine_offer with RTP/AVP and send another
invite to the same device.
In the branch failure route I seem to have to read the current $ru and then
write it back into $ru before calling t_relay() or I get Sep 14 14:56:06
registrar-secure /usr/sbin/kamailio[10168]: ERROR: tm [t_fwd.c:1771]:
t_forward_nonack(): ERROR: t_forward_nonack: no branches for forwarding
This code seems to work, but it feels like I’m doing something very wrong….
in particular $avp(triedrtpout) is set for the transaction, I should be
setting it separately for each branch. event_route[tm:branch-failure:SRTP]
{ # Handle failure response
xlog("L_INFO", "Handling $T_reply_code response to $rm to ru:
<$ru>
and du: $du\n");
if(t_check_status("488") && is_method("INVITE")) {
if ($avp(triedsrtpout)==1) {
# set $ru seems to create a new branch ... even when
we set it to its current value. # we want to generate a new SIP INVITE to
the same AOR but with different SDP $avp(buffer)=$ru;
$ru=$avp(buffer);
xlog("L_INFO","488 caught. Resending to
$ru");
# try with unencrypted RTP/AVP
rtpengine_delete();
rtpengine_offer("to-tag trust-address replace-origin
replace-session-connection ICE=force RTP/AVP"); if (!t_relay()) {
sl_reply_error();
}
}
}
}
I am using kamailio 4.2 debian package for this registrar.
Sorry for the rambling question … I don’t understand enough to write the
short version!
Paul
Paul, I had worked a while back on the exact same thing. Unfortunately for
me, most of my clients are using Zoiper which doesn't seem to handle the re-
invite properly. However, the following worked for me with other clients.
I was already using hash tables to store variables since I have the first
rtpengine_offer in the branch_route.
I use t_reuse_branch() and setbflag(FLB_RTPENGINE_FAILURE), catching the
branch flag when it loops around again in manage_branch so I don't offer again
from there.
I'm not sure all of the below is necessary, but it worked. I'll also be
studying your method as it seems simpler ;)
#!ifdef WITH_RTPENGINE
# Handle branch failure cases
event_route[tm:branch-failure:rtpengine] {
if(t_check_status("415|488")) {
# Ok, this all works, except that Zoiper doesn't recognize the
change in
# Via header (branch) in the updated re-offer branch as an
update, and
# replies with 482 Merged Request -- which fails.
t_reuse_branch();
setbflag(FLB_RTPENGINE_FAILURE);
if($sht(rtpengine=>$ci::$T_branch_idx::offer)=~"RTP/AVP") {
$sht(rtpengine=>$ci::$T_branch_idx::offer)="via-
branch=extra replace-origin replace-session-connection reset RTP/SAVP";
} else if($sht(rtpengine=>$ci::$T_branch_idx::offer)=~"RTP/
SAVP") {
$sht(rtpengine=>$ci::$T_branch_idx::offer)="via-
branch=extra replace-origin replace-session-connection reset RTP/AVP";
}
xlog("L_INFO", "event_route[branch-failure:rtpengine]: NEW:
$sht(rtpengine=>$ci::$T_branch_idx::offer)\n");
rtpengine_offer($sht(rtpengine=>$ci::$T_branch_idx::offer));
# Reset destination URI and sending socket
$du=$sht(rtpengine=>$ci::$T_branch_idx::du);
$fs=$null;
route(RELAY);
exit;
}
}
#!endif
On a side note, a lot of this could be mitigated if I could get $xavp(ulattrs)
to work after a call to alias_db_lookup() followed by
lookup_branches("location") -- the branch indexes get out of sync with those
in the $xavp :(
--
Anthony - https://messinet.com/ - https://messinet.com/~amessina/gallery
F9B6 560E 68EA 037D 8C3D D1C9 FF31 3BDB D9D8 99B6
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days inactive
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3 comments
3 participants
participants (3)
-
Anthony Joseph Messina -
Daniel-Constantin Mierla -
Paul Smith