13 Dec
2004
13 Dec
'04
11:17 p.m.
Hi,
This is my problem:
I'm trying to implement a "hunt group" using t_on_failure directive and an
external script. The script gets the current URI and return the next URI in
the group.
The problem is that after the second INVITE, SER adds some characters before
the INVITE message, and some devices don't understand this "XX INVITES".
Has anyone done something similar? or had a similar poblem?
I'm using:
OS: Redhat Linux 9
Kernel: 2.4.20-16.9
SER: ser 0.8.12 (i386/linux)
For testing I'm using a couple Cisco ATAs, according to the diagram:
______
Line 1 ---/ \ |
| ATA1 |---| ____ _ _ _ _ ____ _ _ _
Line 2 ---\______/ | / \ / \/ \/ \/ \ / \ / \/ \/ \
______ |---| FW |---| IP Net |---| GW |---| PSTN |
Line 3 ---/ \ | \____/ \_/\_/\_/\_/ \____/ \_/\_/\_/
| ATA2 |---| | | |
Line 4 ---\______/ | | | |
| | |
--- --- ---
/ \ / \ / O \
|NAT| |SER| /_\
|-T | | |
\___/ \___/ Phone
My config file is:
######################################################################
# SER Config File
######################################################################
######################################################################
# Global prams
######################################################################
/* Uncomment these lines to enter debugging mode
debug=7
fork=no
log_stderror=yes
*/
check_via=no # (cmd. line: -v)
dns=no # (cmd. line: -r)
rev_dns=no # (cmd. line: -R)
#port=5060
#children=4
fifo="/tmp/ser_fifo"
######################################################################
# Load Modules
######################################################################
loadmodule "/usr/lib/ser/modules/mysql.so" /*MySQL DB Module*/
loadmodule "/usr/lib/ser/modules/sl.so" /*Stateless routing*/
loadmodule "/usr/lib/ser/modules/tm.so" /*Statefull routing*/
loadmodule "/usr/lib/ser/modules/rr.so" /*Record Routing*/
loadmodule "/usr/lib/ser/modules/maxfwd.so" /*Max-fwd header logic*/
loadmodule "/usr/lib/ser/modules/usrloc.so" /*User Location*/
loadmodule "/usr/lib/ser/modules/registrar.so" /*SIP Register functions*/
loadmodule "/usr/lib/ser/modules/exec.so" /*Execute external
commands*/
loadmodule "/usr/lib/ser/modules/auth.so" /*User authentication*/
loadmodule "/usr/lib/ser/modules/auth_db.so" /*User auth. using MySQL
DB*/
loadmodule "/usr/lib/ser/modules/group.so" /*Group commands*/
######################################################################
# Module Params
######################################################################
# -- usrloc params --
modparam("usrloc", "db_mode", 2)
modparam("usrloc", "db_url",
"sql://user:pass@localhost/ser")
# -- auth params --
modparam("auth_db", "db_url",
"sql://user:pass@localhost/ser")
modparam("auth_db", "calculate_ha1", yes)
modparam("auth_db", "password_column", "password")
# -- rr params --
# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 0)
# -- group params --
modparam("group", "db_url",
"sql://user:pass@localhost/ser")
######################################################################
# Server Aliases
######################################################################
alias="mcm.net.mx"
alias="X.X.81.94"
######################################################################
# Main Routing Logic
######################################################################
route{
# Initial sanity checks
if (!mf_process_maxfwd_header("15")) {
sl_send_reply("483","Too Many Hops");
break;
};
if ( msg:len > max_len ) {
sl_send_reply("513", "Message too big");
break;
};
if (loose_route()) {
setflag(2);
t_relay();
break;
};
record_route();
# Registering routines
if (method=="REGISTER") {
if (!www_authorize("mcm.net.mx", "subscriber")) {
www_challenge("mcm.net.mx", "0");
log(1,"User Rejected, challenge sent.");
break;
};
save("location");
break;
};
# Check the source of call and auth. if required
# If the call comes from the gateways, no authentication is
# required (X.X.81.67 or X.X.84.67)
if (src_ip==X.X.81.67 or src_ip==X.X.84.67) {
# Check if the user accept calls
log(1,"Call from pstn. \n");
} else {
if (method=="INVITE") {
if (!proxy_authorize("mcm.net.mx", "subscriber")) {
proxy_challenge("mcm.net.mx", "0");
break;
};
}; # INVITE to authorized PSTN
}
# Routing plan
if (uri=~"^sip:5559853[0-9][0-9][0-9]@.*") {
if (!lookup("location")) {
if (is_user_in("Request-URI", "hg")) {
exec_dset("/usr/scripts/huntgroup2 $SIP_ORUI
1 ");
if (uri=~"^sip:[0-9]+@.*") {
append_branch();
# Set fealiure route for Hunt Groups
t_on_failure("1");
t_relay();
};
} else {
setflag(3);
sl_send_reply("404", "Not Found");
break;
};
} else {
if ( is_user_in("Request-URI", "hg") ) {
# Set fealiure route for Hunt Groups
t_on_failure("1");
};
# Try to send call to dest.
if (!t_relay()) {
sl_reply_error();
};
};
# Forward numeric uri's to PSTN gateways
} else if (uri=~"^sip:[0|1|2|3|5|8|9][0-9]*@.*") {
rewritehost("X.X.81.67");
t_relay();
} else {
sl_send_reply("403", "Call cannot be served here");
break;
};
}
# Hunt group routes
failure_route[1] {
log(1,"First number bysy, try next.\n");
# forwarding failed -- try again at another destination
exec_dset("/usr/scripts/huntgroup2 $SIP_ORUI 1 ");
append_branch();
if (uri=~"^sip:[0-9]+@.*") {
# Set next faliure route
t_on_failure("2");
};
t_relay();
}
failure_route[2] {
log(1,"Next number busy, try next.\n");
# forwarding failed -- try again at another destination
exec_dset("/usr/scripts/huntgroup2 $SIP_ORUI 0 ");
append_branch();
if (uri=~"^sip:[0-9]+@.*") {
t_on_failure("2");
};
t_relay();
}
######################################################################
# End SER Config File
######################################################################
Next is a signaling diagram of a failed call. Lines 1 and 2 of the above
diagram were busy at the time of this trace.
The malformed INVITEs are shown as "XX INVITE".
Gateway SER NAT-T ATA1 ATA2
X.X.81.67 X.X.81.94 X.X.81.92 Y.Y.1.2 Y.Y.1.3
| | | | |
|-- INVITE -------->| | | |
|<-- trying --------| | | |
| |-- INVITE -------->| | |
| |<-- Trying --------| | |
| | |-- INVITE -------->| |
| | |<-- Trying --------| |
| | |<-- Busy ----------| |
| |<-- Busy ----------| | |
| |-- ACK ----------->| | |
| | |-- ACK ----------->| |
| |-- INVITE -------->| | |
| |<-- Trying --------| | |
| | |-- INVITE -------->| |
| | |<-- Trying --------| |
| | |<-- Busy ----------| |
| |<-- Busy ----------| | |
| |-- ACK ----------->| | |
| | |-- ACK ----------->| |
| |-- XX INVITE ----->| | |
| |<-- Trying --------| | |
| | |-- XX INVITE ------------->|
| | |-- XX INVITE ------------->|
| | |-- XX INVITE ------------->|
| | |-- XX INVITE ------------->|
| | |-- XX INVITE ------------->|
| |<-- Req. Timeout --| | |
| | |-- CANCEL ---------------->|
| |-- ACK ----------->| | |
| | |-- ACK ------------------->|
| | |<-- 481 CL/TDNE -----------|
| |<-- 481 CL/TDNE ---| | |
| |-- XX INVITE ----->| | |
| | |-- XX INVITE ------------->|
| |-- XX INVITE ----->| | |
| | |-- XX INVITE ------------->|
| | |<-- Trying ----------------|
| |<-- Trying --------| | |
| | |<-- Trying ----------------|
| |<-- Trying --------| | |
|-- CANCEL -------->| | | |
|<-- cancelling ----| | | |
|<- Req. Candelled -| | | |
|-- ACK ----------->| | | |
| |-- CANCEL -------->| | |
| | |-- CANCEL ---------------->|
| |-- CANCEL -------->| | |
| | |-- CANCEL ---------------->|
| | |<-- 481 CL/TDNE -----------|
| |<-- 481 CL/TDNE ---| | |
Following I pasted the INVITE messages. Those were taken using ngrep.
The malformed INVITE looks like: (notice the extra spaces ath the begining)
#
U X.X.81.94:5060 -> X.X.81.92:5063 31525@0:1480
.`INVITE sip:5559853977*sip.mcm.net.mx=200.52.71.2+24225@X.X.81.92:5063
SIP/2.0
Record-Route: <sip:5559853977@X.X.81.94;ftag=5D03E50C-1912;lr>
Record-Route: <sip:5559853979@X.X.81.94;ftag=5D03E50C-1912;lr>
Record-Route: <sip:5559853978@X.X.81.94;ftag=5D03E50C-1912;lr>
Via: SIP/2.0/UDP X.X.81.94;branch=z9hG4bKf78b.baa0d9c3.0
Via: SIP/2.0/UDP X.X.81.94;branch=z9hG4bKf78b.aaa0d9c3.1
Via: SIP/2.0/UDP X.X.81.94;branch=z9hG4bKf78b.9aa0d9c3.1
Via: SIP/2.0/UDP X.X.81.67:5060
From: <sip:5553500000@X.X.81.67>;tag=5D03E50C-1912
To: <sip:5559853978@X.X.81.94>
Date: Thu, 27 Apr 2000 11:34:27 GMT
Call-ID: 9F4D4C1D-1B6611D4-BFD5E894-B9E38BE3(a)X.X.81.67
Supported: timer,100rel
Min-SE: 1800
Cisco-Guid: 2672603125-459674068-3218270356-3118697443
User-Agent: Cisco-SIPGateway/IOS-12.x
Allow: INVITE, OPTIONS, BYE, CANCEL, ACK, PRACK,COMET, REFER, SUBSCRIBE,
NOTIFY, INFO
CSeq: 101 INVITE
Max-Forwards: 3
Remote-Party-ID:
<sip:5553500000@X.X.81.67>;party=calling;screen=yes;privacy=off
Timestamp: 956835267
Contact: <sip:5553500000@X.X.81.67:5060>
Expires: 180
Allow-Events: telephone-event
Content-Type: application/sdp
Content-Length: 324
v=0
o=CiscoSystemsSIP-GW-UserAgent 8289 4267 IN IP4 X.X.81.67
s=SIP Call
c=IN IP4 X.X.81.67
t=0 0
m=audio 18280 RTP/AVP 8 0 18 100 19
c=IN IP4 X.X.81.67
a=rtpmap:8 PCMA/8000
a=rtpmap:0PCMU/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:100 X-N
While the first INVITE looks like:
#
U X.X.81.67:56763 -> X.X.81.94:5060
INVITE sip:5559853978@X.X.81.94:5060 SIP/2.0
Via: SIP/2.0/UDP X.X.81.67:5060
From: <sip:5553500000@X.X.81.67>;tag=5D03A270-1598
To: <sip:5559853978@X.X.81.94>
Date: Thu, 27 Apr 2000 11:34:10 GMT
Call-ID: 9523FA8C-1B6611D4-BFC2E894-B9E38BE3(a)X.X.81.67
Supported: timer,100rel
Min-SE: 1800
Cisco-Guid: 2502123108-459674068-3217025172-3118697443
User-Agent: Cisco-SIPGateway/IOS-12.x
Allow: INVITE, OPTIONS, BYE, CANCEL, ACK, PRACK, COMET, REFER, SUBSCRIBE,
NOTIFY, INFO
CSeq: 101 INVITE
Max-Forwards: 6
Remote-Party-ID:
<sip:5553500000@X.X.81.67>;party=calling;screen=yes;privacy=off
Timestamp: 956835250
Contact: <sip:5553500000@X.X.81.67:5060>
Expires: 180
Allow-Events: telephone-event
Content-Type: application/sdp
Content-Length: 324
v=0
o=CiscoSystemsSIP-GW-UserAgent 8099 5647 IN IP4 X.X.81.67
s=SIP Call
c=IN IP4 X.X.81.67
t=0 0
m=audio 17162 RTP/AVP 8 0 18 100 19
c=IN IP4 X.X.81.67
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194
a=rtpmap:19 CN/8000
Jesus