[Serusers] Duplicate SIP messages?
Iqbal
iqbal at gigo.co.uk
Mon Jun 27 00:54:46 CEST 2005
Its Sunday night, so please double check anything I write :-)
Although I cant be a 100% for sure it seems as if you SER is just sending
another INVITE this could be due to not receiving a reply in time, how
long b4 the reply comes from the itsp, I think default in ser is 120secs
or something.
If this is not the case, any chance of seeing what the itsp is throwing
up when you send a request, might be something to do with the sdp,
although ser doesnt really do much when it comes to codec/sdp parameter
negotiation
Iqbal
On 6/26/2005, "Tim Pushor" <timp at crossthread.com> wrote:
>Hi Friends,
>
>I am trying to learn ser and wrap my head around the routing logic. My
>first project is a simple outbound proxy to handle SIP/RTP from an
>SPA2000 behind a NAT. The ser server is on the public Internet, but I am
>having trouble making it work :( The spa2000 has been reset to default,
>and basically setup the same way that I'd set it up for FWD behind nat).
>
>I am using an example config from the Internet as as starting point
>(included below) and running on Ser 0.8.14 on FreeBSD (from a port). I
>am using the RTP proxy from ser cvs. This , It almost works, and
>capturing the traffic with ethereal looks to be mostly correct, but I am
>seeing duplicate sip messages (plz excuse formatting), which I think is
>causing me a big problem (even if it isn't, I'd like to know why this is
>happening).
>
>I didn't include frames 1 and 2, they are a SIP keepalive.
>
>3 is the request from the spa2000 to the proxy
>4 is the response from the proxy
>5 is the request from the proxy to the itsp
>6 is a dup!
>And then the problem compounds as the itsp tries to connect the same
>call twice.
>
>I would be very appreciative of any advice from you veterans ;-)
>
>Thanks,
>Tim
>
>** Doctored trace
>
>- 207.46.199.15 is the address of the NAT
>- 207.46.199.14 is the address of the Proxy running ser
>- 69.16.138.164 is the address of my itsp's SIP proxy
>
> 3 4.563455 207.46.199.15 207.46.199.14
>SIP/SDP Request: INVITE sip:6415551234 at my.itsp.com, with session
>description
> 4 4.564809 207.46.199.14 207.46.199.15
>SIP Status: 100 trying -- your call is important to us
> 5 4.566539 207.46.199.14 69.16.138.164 SIP/SDP
>Request: INVITE sip:6415551234 at my.itsp.com, with session description
> 6 4.578979 207.46.199.14 69.16.138.164 SIP/SDP
>Request: INVITE sip:6415551234 at my.itsp.com, with session description
> 7 4.589856 69.16.138.164 207.46.199.14 SIP
>Status: 100 Trying
> 8 4.602580 69.16.138.164 207.46.199.14 SIP
>Status: 407 Proxy Authorization Required
> 9 4.602733 207.46.199.14 69.16.138.164 SIP
>Request: ACK sip:6415551234 at my.itsp.com
> 10 4.602808 207.46.199.14 207.46.199.15
>SIP Status: 407 Proxy Authorization Required
> 11 4.611428 69.16.138.164 207.46.199.14 SIP
>Status: 407 Proxy Authorization Required
> 12 4.611574 207.46.199.14 69.16.138.164 SIP
>Request: ACK sip:6415551234 at my.itsp.com
> 13 4.613772 207.46.199.15 207.46.199.14
>SIP Request: ACK sip:6415551234 at my.itsp.com
> 14 4.622070 207.46.199.15 207.46.199.14
>SIP/SDP Request: INVITE sip:6415551234 at my.itsp.com, with session
>description
> 15 4.623428 207.46.199.14 207.46.199.15
>SIP Status: 100 trying -- your call is important to us
> 16 4.625164 207.46.199.14 69.16.138.164 SIP/SDP
>Request: INVITE sip:6415551234 at my.itsp.com, with session description
> 17 4.648612 69.16.138.164 207.46.199.14 SIP
>Status: 100 Trying
> 18 7.101641 69.16.138.164 207.46.199.14 SIP
>Status: 180 Ringing
> 19 7.101844 207.46.199.14 207.46.199.15
>SIP Status: 180 Ringing
> 20 7.601009 69.16.138.164 207.46.199.14 SIP
>Status: 180 Ringing
> 21 7.601206 207.46.199.14 207.46.199.15
>SIP Status: 180 Ringing
> 22 8.859386 69.16.138.164 207.46.199.14 SIP
>Status: 180 Ringing
> 23 8.859577 207.46.199.14 207.46.199.15
>SIP Status: 180 Ringing
>.....
>.....
>
>My config:
>
># ----------- global configuration parameters ------------------------
>
>fork=no
>log_stderror=yes
>debug=7
>
>check_via=no # (cmd. line: -v)
>dns=no # (cmd. line: -r)
>rev_dns=no # (cmd. line: -R)
>port=5060
>children=1
>fifo="/tmp/ser_fifo"
>
># ------------------ module loading ----------------------------------
>
>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"
>loadmodule "/usr/local/lib/ser/modules/textops.so"
>
># !! Nathelper
>loadmodule "/usr/local/lib/ser/modules/nathelper.so"
>
># ----------------- setting module-specific parameters ---------------
>
># -- usrloc params --
>
>modparam("usrloc", "db_mode", 0)
>
># -- rr params --
># add value to ;lr param to make some broken UAs happy
>modparam("rr", "enable_full_lr", 1)
>
># !! Nathelper
>modparam("registrar", "nat_flag", 6)
>modparam("nathelper", "natping_interval", 30) # Ping interval 30 s
>modparam("nathelper", "ping_nated_only", 1) # Ping only clients behind NAT
>
># ------------------------- request routing logic -------------------
>
># main routing logic
>
>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;
> };
>
> # !! Nathelper
> # Special handling for NATed clients; first, NAT test is
> # executed: it looks for via!=received and RFC1918 addresses
> # in Contact (may fail if line-folding is used); also,
> # the received test should, if completed, should check all
> # vias for rpesence of received
> if (nat_uac_test("3")) {
> # Allow RR-ed requests, as these may indicate that
> # a NAT-enabled proxy takes care of it; unless it is
> # a REGISTER
>
> if (method == "REGISTER" || ! search("^Record-Route:")) {
> log("LOG: Someone trying to register from private
>IP, rewriting\n");
>
> # This will work only for user agents that support
>symmetric
> # communication. We tested quite many of them and
>majority is
> # smart enough to be symmetric. In some phones it
>takes a configuration
> # option. With Cisco 7960, it is called
>NAT_Enable=Yes, with kphone it is
> # called "symmetric media" and "symmetric signalling".
>
> fix_nated_contact(); # Rewrite contact with source
>IP of signalling
> if (method == "INVITE") {
> fix_nated_sdp("1"); # Add direction=active to SDP
> };
> force_rport(); # Add rport parameter to topmost Via
> setflag(6); # Mark as NATed
> };
> };
>
> # 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=="REGISTER") record_route();
>
> # subsequent messages withing a dialog should take the
> # path determined by record-routing
> if (loose_route()) {
> # mark routing logic in request
> append_hf("P-hint: rr-enforced\r\n");
> route(1);
> break;
> };
>
> if (!uri==myself) {
> # mark routing logic in request
> append_hf("P-hint: outbound\r\n");
> route(1);
> 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") {
>
> save("location");
> break;
> };
>
> lookup("aliases");
> if (!uri==myself) {
> append_hf("P-hint: outbound alias\r\n");
> route(1);
> break;
> };
>
> # native SIP destinations are handled using our USRLOC DB
> if (!lookup("location")) {
> sl_send_reply("404", "Not Found");
> break;
> };
> };
> append_hf("P-hint: usrloc applied\r\n");
> route(1);
>}
>
>route[1]
>{
> # !! Nathelper
> if (uri=~"[@:](192\.168\.|10\.|172\.(1[6-9]|2[0-9]|3[0-1])\.)"
>&& !search("^Route:")){
> sl_send_reply("479", "We don't forward to private IP
>addresses");
> break;
> };
>
> # if client or server know to be behind a NAT, enable relay
> if (isflagset(6)) {
> force_rtp_proxy();
> };
>
> # NAT processing of replies; apply to all transactions (for example,
> # re-INVITEs from public to private UA are hard to identify as
> # NATed at the moment of request processing); look at replies
> t_on_reply("1");
>
> # send it out now; use stateful forwarding as it works reliably
> # even for UDP2TCP
> if (!t_relay()) {
> sl_reply_error();
> };
>}
>
># !! Nathelper
>onreply_route[1] {
> # NATed transaction ?
> if (isflagset(6) && status =~ "(183)|2[0-9][0-9]") {
> fix_nated_contact();
> if (!( search ("^Content-Length:\ 0") )) {
> force_rtp_proxy();
> }
> # otherwise, is it a transaction behind a NAT and we did not
> # know at time of request processing ? (RFC1918 contacts)
> } else if (nat_uac_test("1")) {
> fix_nated_contact();
> };
>}
>
>
>
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