[Serusers] Re: SER Call Forking with Cisco Routers as SIP endpoints
Greger V. Teigre
greger at teigre.com
Fri Feb 25 09:56:40 CET 2005
I had a look at your previous post, but forgot to answer...
My guess is that an ngrep or ethereal on the SDP part of the INVITEs between
router1 and router will show that there is something wrong in the IP address
or port number in the c= and m= lines of SDP. It's pretty logical:
- The INVITE c= should contain router1's IP address, m= should contain the
user agent's allocated RTP port
- router2's OK should contain router2's IP address, and so on
You check on router1 and router2 which ports the user agents are listening
on, look at the INVITE and the OK and see if they match. Compare that to the
RTP stream you see, from where to where?
If these ports do not match, find out why...
g-)
Psyber wrote:
> Anyone have any ideas on this? I'm considering setting up
> rtpproxy as a temporary workaround (assuming that will somehow
> mitigate the issue), but given my evironment it won't be a feasible
> production solution. I'm still pretty baffled as to why parties can
> talk between router1 and router3, router2 and router 3, but not
> between router1 and router2. Further confusing the situation is the
> fact that the call completes just fine when calling between router1
> and router 2 and an RTP stream is established between the two routers,
> just no sound. router1 and router2 have a clear path to each other.
>
>
> On Thu, 17 Feb 2005 18:41:04 -0500, Psyber <psyber1 at gmail.com> wrote:
>> I'm presently working on a SIP setup whereby there are 3 Cisco
>> routers which each have analog phones connected to them via FXS
>> ports. All 3 of these routers are connected via an underlying
>> network. I
>> have a machine hanging off from one of these routers running ser.
>> For ease of labelling, I'll call these routers: router1, router2, and
>> router3 (SIP server directly connected to this router via ethernet).
>> I'm attempting to setup call forking using the UsrLoc database (this
>> will eventually be SQL, but for the sake of the short-term I'm just
>> storing UsrLoc in memory). The desired call forking setup looks
>> something like this:
>>
>> router1 --> router2
>> --> router 3
>>
>> router 2 --> router 1
>> --> router 3
>>
>> router 3 --> router 1
>> --> router 2
>>
>> I am able to complete calls between router1 and router3 (and
>> vice-versa) and carry on a conversation, but when calling between
>> router1 and router2 the call completes, but neither party can hear
>> the other. Ironically, router1 and router2 are sitting right next
>> to each other (though, connected via another router). However, The
>> SIP proxy
>> is directly connected to router3. Doing a 'debug voip rtp' I see RTP
>> messages travel bidirectionally in a constant stream with correct IP
>> addresses and ports until the call ends, but at no point during the
>> conversation can either party hear the other. This would lead me to
>> believe that something other than SIP was at play, but when I bypass
>> the proxy (point the two routers directly at each other via the
>> dial-peer) call completion works and both parties can hear each other
>> (I set these up as SIP, not the default H.323). Below is my ser.cfg
>> file and the output of 'serctl ul show' for the static UsrLoc entries
>> that I've created. The routers are setup with simple dial-peers and
>> a sip-ua.
>>
>> I've verified that there isn't any type of ACL or firewall to
>> obstruct the conversation. Every router is able to reach each other
>> router as well as the proxy server. I'm using private address space
>> at present, but NAT isn't being done at any point. I've pondered
>> trying rtp_proxy and forcing the bearer (RTP) traffic through the
>> proxy, but that isn't
>> a particularly good solution for my environment.
>>
>> Any help would be greatly appreciated. I'm hoping that it's just a
>> case of broken logic in my ser.cfg. Please CC: this address in your
>> reply as I'm not currently on the mailing list.
>>
>> Most of the configuration is derived from the sample configurations
>> that I ran into.
>>
>> ---ser.cfg start---
>>
>> # ----------- global configuration parameters
>> ------------------------
>>
>> debug=7 # debug level (cmd line: -dddddddddd)
>> fork=yes
>> log_stderror=yes # (cmd line: -E)
>>
>> /* 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)
>> listen=192.168.1.2
>> port=5060
>> mhomed=1
>> #children=4
>> fifo="/tmp/ser_fifo"
>>
>> # ------------------ module loading
>> ----------------------------------
>>
>> # Uncomment this if you want to use SQL database
>> #loadmodule "/usr/local/lib/ser/modules/mysql.so"
>>
>> loadmodule "/usr/local/lib/ser/modules/sl.so"
>> loadmodule "/usr/local/lib/ser/modules/tm.so"
>> loadmodule "/usr/local/lib/ser/modules/rr.so"
>> loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
>> loadmodule "/usr/local/lib/ser/modules/usrloc.so"
>> loadmodule "/usr/local/lib/ser/modules/registrar.so"
>>
>> # Uncomment this if you want digest authentication
>> # mysql.so must be loaded !
>> #loadmodule "/usr/local/lib/ser/modules/auth.so"
>> #loadmodule "/usr/local/lib/ser/modules/auth_db.so"
>>
>> # ----------------- setting module-specific parameters
>> ---------------
>>
>> # -- usrloc params --
>>
>> modparam("usrloc", "db_mode", 0)
>>
>> # Uncomment this if you want to use SQL database
>> # for persistent storage and comment the previous line
>> #modparam("usrloc", "db_mode", 2)
>>
>> # -- auth params --
>> # Uncomment if you are using auth module
>> #
>> #modparam("auth_db", "calculate_ha1", yes)
>> #
>> # If you set "calculate_ha1" parameter to yes (which true in this
>> config), # uncomment also the following parameter)
>> #
>> #modparam("auth_db", "password_column", "password")
>>
>> # -- rr params --
>> # add value to ;lr param to make some broken UAs happy
>> modparam("rr", "enable_full_lr", 1)
>>
>> # ------------------------- request routing logic
>> -------------------
>>
>> # main routing logic
>> alias="ser"
>>
>> route{
>>
>> # initial sanity checks -- messages with
>> # max_forwards==0, or excessively long requests
>> if (!mf_process_maxfwd_header("10")) {
>> sl_send_reply("483","Too Many Hops");
>> break;
>> };
>> if (msg:len > max_len ) {
>> sl_send_reply("513", "Message too big");
>> break;
>> };
>>
>> # we record-route all messages -- to make sure that
>> # subsequent messages will go through our proxy; that's
>> # particularly good if upstream and downstream entities
>> # use different transport protocol
>> if (method=="INVITE") record_route();
>>
>> # loose-route processing
>> if (loose_route()) {
>> t_relay();
>> break;
>> };
>>
>> # if the request is for other domain use UsrLoc
>> # (in case, it does not work, use the following command
>> # with proper names and addresses in it)
>> if (uri==myself) {
>>
>> if (method=="REGISTER") {
>>
>> # Uncomment this if you want to use digest authentication
>> # if (!www_authorize("iptel.org",
>> "subscriber")) { #
>> www_challenge("iptel.org", "0"); #
>> break; # };
>>
>> save("location");
>> break;
>> };
>>
>> # native SIP destinations are handled using our
>> USRLOC DB if (!lookup("location")) {
>> sl_send_reply("404", "Not Found");
>> break;
>> };
>> };
>> # forward to current uri now; use stateful forwarding; that
>> # works reliably even if we forward from TCP to UDP
>> if (!t_relay()) {
>> sl_reply_error();
>> };
>>
>> }
>>
>> ---end ser.cfg---
>>
>> ---start static UsrLoc entries---
>>
>> ser# ../../sbin/serctl ul show 222
>> 200 OK
>> <sip:222@<router2 IP>:5060>;q=1.00;expires=1003718231
>> <sip:222@<router3 IP>:5060>;q=1.00;expires=1003718231
>>
>> ser# ../../sbin/serctl ul show 111
>> 200 OK
>> <sip:111@<router1 IP>:5060>;q=1.00;expires=1003718231
>> <sip:111@<router3 IP>:5060>;q=1.00;expires=1003718231
>>
>> ser# ../../sbin/serctl ul show 333
>> 200 OK
>> <sip:111@<router1 IP>:5060>;q=1.00;expires=1003718231
>> <sip:222@<router2 IP>:5060>;q=1.00;expires=1003718231
>>
>> ---end static UsrLoc entries---
>>
>> Thank you.
>>
>
> _______________________________________________
> Serusers mailing list
> serusers at lists.iptel.org
> http://lists.iptel.org/mailman/listinfo/serusers
More information about the sr-users
mailing list