## TEMPLATE RENDER CMD: sed "s|{{SIP_IP}}|184.106.171.135|g;s|{{SIP_PORT}}|5060|g;s|{{SIP_TLS_PORT}}|5061|g" opensips.tmp > opensips.cfg
######################################################################
## Core Parameters
######################################################################
# chroot=
# group="opensips"
# user="opensips"
# dbversion_table=
disable_core_dump=no
max_while_loops=100
maxbuffer=262144
memdump=3
memlog=2
# open_files_limit=2048
server_signature=no
server_header="Server: 2600hz"
user_agent_header="User-Agent: 2600hz"

######################################################################
## Core Fork Parameters
######################################################################
fork=yes
children=8
tcp_children=8

######################################################################
## Core Logging Parameters
######################################################################
debug=3
sip_warning=0
log_stderror=no
log_facility=LOG_LOCAL0
log_name="opensips"

######################################################################
## Aliases
######################################################################
auto_aliases=yes
alias=localhost
alias=localhost.localdomain

######################################################################
## Connectivity
######################################################################
listen=udp:eth0:{{SIP_PORT}}
listen=udp:eth0:7000
listen=tcp:eth0:{{SIP_PORT}}
listen=tcp:eth0:7000
tos=IPTOS_LOWDELAY
# advertised_address={{SIP_IP}}
# advertised_port={{SIP_PORT}}
mcast_loopback=no
mcast_ttl=1
mhomed=0
# tcp_accept_aliases
tcp_connect_timeout=3
tcp_connection_lifetime=120
tcp_max_connections=2048
# tcp_poll_method=select

######################################################################
## DNS
######################################################################
dns=no
dns_retr_time=1
dns_retr_no=3
# dns_servers_no=2
dns_try_ipv6=no
disable_dns_blacklist=yes
disable_dns_failover=no
dns_use_search_list=no
rev_dns=no

######################################################################
## SIP
######################################################################
check_via=0
#! disable_503_translation=no
disable_stateless_fwd=no
disable_tcp=no
# disable_tls=no
#! reply_to_via=1

######################################################################
## TLS
######################################################################
# disable_tls=no
# listen=tls:{{SIP_IP}}:{{SIP_TLS_PORT}}
# tls_verify_server=1
# tls_verify_client=1
# tls_require_client_certificate=0
# tls_method=TLSv1
# tls_certificate="/usr/local/etc/opensips/tls/user/user-cert.pem"
# tls_private_key="/usr/local/etc/opensips/tls/user/user-privkey.pem"
# tls_ca_list="/usr/local/etc/opensips/tls/user/user-calist.pem"

######################################################################
## Destination Blacklist
######################################################################
# dst_blacklist=gw:{( tcp , 192.168.2.100 , 5060 , "" ),( any , 192.168.2.101 , 0 , "" )}
# dst_blacklist=net_filter2:{ !( any , 192.168.30.0/255.255.255.0 , 0 , "" )}

######################################################################
## Attribute Value Pairs
######################################################################
# avp_aliases="uuid=I:660;email=s:email_addr;fwd=i:753"

######################################################################
## Module Loading
######################################################################
mpath="/usr/lib64/opensips/modules/"
loadmodule "localcache.so"
loadmodule "signaling.so"
loadmodule "sl.so"
loadmodule "tm.so"
loadmodule "dialog.so"
loadmodule "maxfwd.so"
loadmodule "rr.so"
loadmodule "path.so"
loadmodule "uri.so"
loadmodule "textops.so"
loadmodule "usrloc.so"
loadmodule "nathelper.so"
loadmodule "nat_traversal.so"
loadmodule "dispatcher.so"
loadmodule "mi_fifo.so"
# loadmodule "mi_datagram.so"
# loadmodule "xlog.so"

######################################################################
## Localcache Module Parameters
######################################################################
modparam("localcache", "cache_table_size", 10)
modparam("localcache", "cache_clean_period", 120)

######################################################################
## Stateless UA Module Parameters
######################################################################
modparam("sl", "enable_stats", 1)

######################################################################
## SIP Transaction UA Module Parameters
######################################################################
modparam("tm", "fr_timer", 2)
modparam("tm", "fr_inv_timer", 120)
# modparam("tm", "wt_timer", 5)
# modparam("tm", "delete_timer", 2)
# modparam("tm", "T1_timer", 500)
# modparam("tm", "T2_timer", 4000)
# modparam("tm", "ruri_matching", 1)
# modparam("tm", "via1_matching", 1)
# modparam("tm", "unix_tx_timeout", 2)
# modparam("tm", "restart_fr_on_each_reply", 1)
modparam("tm", "fr_timer_avp", "$avp(s:final_reply_timer)")
# modparam("tm", "fr_inv_timer_avp", "$avp(s:final_reply_prov)")
# modparam("tm", "tw_append",
#    "test: ua=$hdr(User-Agent) ;avp=$avp(i:10);$rb;time=$Ts")
modparam("tm", "pass_provisional_replies", 1)
# modparam("tm", "syn_branch", 1)
# modparam("tm", "onreply_avp_mode", 0)
# modparam("tm", "disable_6xx_block", 0)
# modparam("tm", "enable_stats", 1)
# modparam("tm", "minor_branch_flag", 3)

######################################################################
## Max Forward Module Parameters
######################################################################
modparam("maxfwd", "max_limit", 30)

######################################################################
## Record Route Module Parameters
######################################################################
modparam("rr", "enable_full_lr", 1)
modparam("rr", "append_fromtag", 1)
modparam("rr", "enable_double_rr", 0)
modparam("rr", "add_username", 0)

######################################################################
## Path Module Parameters
######################################################################
modparam("path", "use_received", 1)

######################################################################
## URI Module Parameters
######################################################################
# modparam("uri", "aaa_url", "radius:/etc/radiusclient-ng/radiusclient.conf")
modparam("uri", "use_sip_uri_host", 0)
modparam("uri", "use_uri_table", 0)
modparam("uri", "service_type", 10)
modparam("uri", "use_domain", 1)
modparam("uri", "use_uri_table", 0)
# modparam("uri", "db_url", "mysql://username:password@localhost/opensips")
# modparam("uri", "db_table", "uri")
# modparam("uri", "user_column", "username")
# modparam("uri", "domain_column", "domain")
# modparam("uri", "uriuser_column", "uri_user")

######################################################################
## User Location Module Parameters
######################################################################
modparam("usrloc", "nat_bflag", 6)
modparam("usrloc", "use_domain", 1)
modparam("usrloc", "desc_time_order", 0)
modparam("usrloc", "timer_interval", 60)
modparam("usrloc", "matching_mode", 0)
modparam("usrloc", "cseq_delay", 20)
modparam("usrloc", "hash_size", 9)
modparam("usrloc", "db_mode", 0)
# modparam("usrloc", "db_url", "dbdriver://username:password@dbhost/dbname")
modparam("usrloc", "fetch_rows", 2000)
modparam("usrloc", "user_column", "username")
modparam("usrloc", "domain_column", "domain")
modparam("usrloc", "contact_column", "contact")
modparam("usrloc", "expires_column", "expires")
modparam("usrloc", "q_column", "q")
modparam("usrloc", "callid_column", "callid")
modparam("usrloc", "cseq_column", "cseq")
modparam("usrloc", "methods_column", "methods")
modparam("usrloc", "flags_column", "flags")
modparam("usrloc", "cflags_column", "cflags")
modparam("usrloc", "user_agent_column", "user_agent")
modparam("usrloc", "received_column", "received")
modparam("usrloc", "socket_column", "socket")
modparam("usrloc", "path_column", "path")

######################################################################
## Nathelper Module Parameters
######################################################################
# modparam("nathelper", "rtpproxy_sock", "udp:127.0.0.1:7890")
# modparam("nathelper", "natping_interval", 30)
# modparam("nathelper", "ping_nated_only", 1)
# modparam("nathelper", "natping_processes", 3)
# modparam("nathelper", "sipping_bflag", 7)
# modparam("nathelper", "sipping_from", "sip:sipcheck@{{SIP_IP}}:{{SIP_PORT}}")
# modparam("nathelper", "sipping_method", "INFO")

######################################################################
## NAT Traversal Module Parameters
######################################################################
modparam("nat_traversal", "keepalive_interval", 60)
modparam("nat_traversal", "keepalive_method", "OPTIONS")
modparam("nat_traversal", "keepalive_from", "sip:keepalive@{{SIP_IP}}:{{SIP_PORT}}")
modparam("nat_traversal", "keepalive_state_file", "/tmp/opensips_keepalive_state")

######################################################################
## Dispatcher Module Parameters
######################################################################
modparam("dispatcher", "list_file", "/etc/opensips/dispatcher.list")
modparam("dispatcher", "flags", 2)
modparam("dispatcher", "use_default", 0)
modparam("dispatcher", "force_dst", 1)
modparam("dispatcher", "dst_avp", "$avp(i:271)")
modparam("dispatcher", "attrs_avp", "$avp(i:272)")
modparam("dispatcher", "grp_avp", "$avp(i:273)")
modparam("dispatcher", "cnt_avp", "$avp(i:274)")
modparam("dispatcher", "hash_pvar", "$avp(i:273)")
# modparam("dispatcher", "setid_pvar", "$var(setid)")
modparam("dispatcher", "ds_ping_method", "OPTIONS")
modparam("dispatcher", "ds_ping_from", "sip:sipcheck@{{SIP_IP}}:{{SIP_PORT}}")
modparam("dispatcher", "ds_ping_interval", 10)
# modparam("dispatcher", "ds_ping_sock", "udp:{{SIP_IP}}:{{SIP_PORT}}")
modparam("dispatcher", "ds_probing_threshhold", 3)
modparam("dispatcher", "ds_probing_mode", 0)
modparam("dispatcher", "options_reply_codes", "501, 403, 404, 400")

######################################################################
## MI-FIFO Module Parameters
######################################################################
modparam("mi_fifo", "fifo_name", "/tmp/opensips_fifo")

######################################################################
## MI-Datagram Module Parameters
######################################################################
# modparam("mi_datagram", "socket_name", "udp:127.0.0.1:8889")
# modparam("mi_datagram", "children_count", 1)
# modparam("mi_datagram", "unix_socket_mode", 0600)
# modparam("mi_datagram", "unix_socket_group", "root")
# modparam("mi_datagram", "unix_socket_user", "root")
# modparam("mi_datagram", "socket_timeout", 2000)
# modparam("mi_datagram", "reply_indent", "\t")

######################################################################
## XLog Module Parameters
######################################################################
# modparam("xlog", "buf_size", 4096)
# modparam("xlog", "force_color", 0)

######################################################################
## Multiple Module Parameters
######################################################################


######################################################################
## Main Request Routing
######################################################################
route
{
    # log the basic info regarding this call
    xlog("L_INFO", "$ci|start|recieved $oP request $rm $ou");
    xlog("L_INFO", "$ci|log|source $si:$sp");
    xlog("L_INFO", "$ci|log|from $fu");
    xlog("L_INFO", "$ci|log|to $tu");

    # check that hop cound for this request and make sure it is under 10
    # to prevent endless loops
    if (!mf_process_maxfwd_header("10"))
    {
        xlog("L_WARN", "$ci|end|to many hops");

        sl_send_reply("483", "We refuse to process this endless imbroglio");

        exit;
    }

    # this check detemines if the opensips has routed the request to itself,
    # this happens because the server is the destination of the request but
    # we mangle it to send it else where.  When that mangeling fails and we
    # still relay it then it just comes right back to us...
    if (src_ip==myself) 
    {
        xlog("L_WARN", "$ci|end|sourced from this server");

        exit;
    }

    # currently we dont support subscribe in whistle so to keep the noise down
    # just end the request here.  For options just end the request here as well.
    if (is_method("OPTIONS|SUBSCRIBE"))
    {
        xlog("L_NOTICE", "$ci|end|unsupported method");

        sl_send_reply("503", "Rawr!!");

        exit;
    }

    # if the source IP/port are in one of the server dispatch lists
    # then this request originated from one of our media servers, mark it
    # as such by setting flag 26
    if (ds_is_in_list("$si", "$sp", "1"))
    {
        xlog("L_INFO", "$ci|log|inception on-net");

        # Flag 26 marks the source as a on-net server   
        setflag(26);
    }
    # if the request source IP/port was not in any dispatcher lists
    # this this originated outside our equipment (carrier, client, ect)
    else
    {
        xlog("L_INFO", "$ci|log|inception off-net");
    }

    # if the to header has a tag attached then it implies this request
    # has been processed by us before (IE: a media server has added
    # its tag on the to header in prior messages)
    if (has_totag())
    {
        # sequential request within a dialog should
        # take the path determined by record-routing
        if (loose_route())
        {
            append_hf("P-hint: rr-enforced\r\n");

            # if the request is an ACK from our media servers with a IP in the from domain
            # then bump the association
            #if ($(fd{ip.isip}) && isflagset(26) && is_method("ACK")) 
            #{
                #cache_store("local", "$tU", "$fd", 3600);

                #xlog("L_INFO", "$ci|log|maintaining contact association to media server $fd");
            #}

            xlog("L_INFO", "$ci|log|forwarding based on the route set");

            route(1);
        }
        else if ( is_method("ACK") )
        {
            if ( t_check_trans() )
            {
                # non loose-route, but stateful ACK; must be an ACK after
                # a 487 or e.g. 404 from upstream server
                xlog("L_INFO", "$ci|log|in dialog request belongs to a known transaction");

                route(1);
            }
            else
            {
                # ACK without matching transaction ->
                # ignore and discard
                xlog("L_NOTICE", "$ci|end|no matching transaction");

                exit;
            }
        }

        # request with a to tag that cant be routed loosly and is not an ACK
        # ignor eand discard
        xlog("L_WARN", "$ci|end|could not route in dialog");

        sl_send_reply("486", "PC Load Letter");

        exit;
    }

    # if the request is to cancel a transaction process it now
    if (is_method("CANCEL"))
    {
        # If this cancel is part of a transaction
        # then pass it along to concerned parties
        if (t_check_trans())
        {
            xlog("L_INFO", "$ci|log|request belogs to a known transaction");

            route(1);
        }
        # if the cancel does not belong to a known transaction or a 
        # request that has not progressed outside this server dont relay it
        else
        {
            xlog("L_NOTICE", "$ci|end|no matching transaction");
        }

        exit;
    }

    # If this is a retransmission it will break/stop the script
    # and do standard processing of the message
    t_check_trans();

    # Except for an ACK no request should have a route set with no to tag, this would
    # indicate that the intial request has the Route headers and is likely someone trying
    # to get us to send the request were they want
    if (loose_route())
    {
        if (!is_method("ACK"))
        {
            xlog("L_WARN", "$ci|end|initial request contained a preloaded route set");

            sl_send_reply("403", "Please leave the routing up to us");

            exit;
        }
    }

    # If the request is a register we will pass it along but we need
    # to add the path header (along with the received IP/port info)
    if (is_method("REGISTER"))
    {
        # if we fail to add the path header then dont let it 
        # register because it will cause issues later...
        if (!add_path_received())
        {
            xlog("L_ERR", "$ci|end|unable to add path");

            sl_send_reply("503", "Internal path befuddlement");

            exit;
        }

        xlog("L_INFO", "$ci|log|added path");
    }

    # if the request is from on of our media servers then dont change the routing
    if (isflagset(26))
    {
        xlog("L_INFO", "$ci|log|originated from internal source");
    }
    else
    {
        if (ds_select_domain("1", "4"))
        {
            xlog("L_INFO", "$ci|log|loaded media server list");
        }
        # if no media server could be set with ds_select_domain then there are no
        # active servers, no need to conitnue
        else
        {
            xlog("L_ERR", "$ci|end|no servers avaliable");

            sl_send_reply("486", "All servers busy");

            exit;
        }
    }

    # if the request is not from our media severs but has a contact uri in localcache 
    # then change the routing to go to the server previously associated with it.
    if ($ct.fields(uri) && cache_fetch("local", "$(ct.fields(uri){uri.user})", $avp(i:55))) 
    {
        xlog("L_INFO", "$ci|log|contact $(ct.fields(uri){uri.user}) is associated with media server $avp(i:55)");

        # if the dispatcher list (in 271) does not start with
        # the request domain/port that we are sending this call
        # to, re-order the list so that it does
        if($(avp(i:271)[0]) != $avp(i:55))
        {
            # create a index var for our loop (arrays are start at 0 and this is a count)
            $var(i) = $avp(i:274) - 1;

            # loop over the dispatcher list
            while($var(i) > 0)
            {
                # if this element in the dispatch list is the same
                # as the call destination
                if($(avp(i:271)[$var(i)]) == $avp(i:55))
                {
                    # replace it with the first element of the list
                    $(avp(i:271)[$(var(i))]) = $(avp(i:271)[0]);

                    # break out of the loop
                    $var(i) = -1;
                }

                $var(i) = $var(i) - 1;
            }

            # handles the case were we only have two servers
            # and the one that we are locked to has failed
            if ($var(i) >= 0)
            {
                xlog("L_INFO", "$ci|log|associated media server is inactive, moving to $rd");

                # leave the randomly choosen server as the destination and
                # overwrite the cache
                cache_store("local", "$(ct.fields(uri){uri.user})", "sip:$rd:$rp", 3600);

                cache_store("local", "$ci", "sip:$rd:$rp", 3600);
            }
            # the server we are locked to is in the active server list from then
            # dispatcher so re-arrange the list to try it first
            else
            {
                xlog("L_INFO", "$ci|log|re-ordering the dispatcher list to keep associated server first");

                # set the first element of the list to the destination
                $(avp(i:271)[0]) = $avp(i:55);

                # set the domain for this request (server IP to route to)
                $rd = $(avp(i:55){uri.host});

                # set the port for this request (server IP to route to)
                $rp = $(avp(i:55){uri.port});
            }
        }
    }
    # if the request is not from our media severs but has a call-id in localcache 
    # then change the routing to go to the server previously associated with it.
    else if (cache_fetch("local", "$ci", $avp(i:55)))
    {
        xlog("L_INFO", "$ci|log|call-id is associated with media server $avp(i:55)");

        # if the dispatcher list (in 271) does not start with
        # the request domain/port that we are sending this call
        # to, re-order the list so that it does
        if($(avp(i:271)[0]) != $avp(i:55))
        {
            # create a index var for our loop (arrays are start at 0 and this is a count)
            $var(i) = $avp(i:274) - 1;

            # loop over the dispatcher list
            while($var(i) > 0)
            {
                # if this element in the dispatch list is the same
                # as the call destination
                if($(avp(i:271)[$var(i)]) == $avp(i:55))
                {
                    # replace it with the first element of the list
                    $(avp(i:271)[$(var(i))]) = $(avp(i:271)[0]);

                    # break out of the loop
                    $var(i) = -1;
                }

                $var(i) = $var(i) - 1;
            }

            # handles the case were we only have two servers
            # and the one that we are locked to has failed
            if ($var(i) >= 0)
            {
                xlog("L_INFO", "$ci|log|associated media server is inactive, moving to $rd");

                # leave the randomly choosen server as the destination and
                # overwrite the cache
                cache_store("local", "$(ct.fields(uri){uri.user})", "sip:$rd:$rp", 3600);

                cache_store("local", "$ci", "sip:$rd:$rp", 3600);
            }
            # the server we are locked to is in the active server list from then
            # dispatcher so re-arrange the list to try it first
            else
            {
                xlog("L_INFO", "$ci|log|re-ordering the dispatcher list to keep associated server first");

                # set the first element of the list to the destination
                $(avp(i:271)[0]) = $avp(i:55);

                # set the domain for this request (server IP to route to)
                $rd = $(avp(i:55){uri.host});

                # set the port for this request (server IP to route to)
                $rp = $(avp(i:55){uri.port});
            }
        }

        if ($ct.fields(uri) && is_method("INVITE")) 
        {
            cache_store("local", "$(ct.fields(uri){uri.user})", "sip:$rd:$rp", 3600);

            xlog("L_INFO", "$ci|log|associated contact $(ct.fields(uri){uri.user}) with media server sip:$rd:$rp");
        }
    }
    # if the request is not from our media servers and no associations in localcache 
    # then used the distribute list as is
    else
    {
        xlog("L_INFO", "$ci|log|routing call to arbitrary media server $rd:$rp");
    }

    # for all initial request (not having been processed above in the has_totag)
    # that are not a register or message add this sever to the route set on the
    # request so subsequent messages come through this server
    if (!is_method("REGISTER|MESSAGE"))
    {
        # Record the route that this request has taken
        # so we remain in the signaling path
        record_route();

        xlog("L_INFO", "$ci|log|added this server to the route set");
    }

    route(1);
}

route[1]
{
    route("nat_test_and_correct");   

    # if the request domain is an IP and it exists in the list of our media servers (irregardless of the port)
    # then...
    # 1. remove any X-AUTH-IP headers so we will be the only one to set it
    # 2. set the X-AUTH-IP header for freeswitch ACLs
    # 3. set the final reply timer to two seconds, so we failover faster
    # 4. arm a logging branch for replies
    # 5. arm a failure branch that will try another one of our media servers when possible
    if ($(rd{ip.isip}) && ds_is_in_list("$rd", "", "1")) 
    {
        remove_hf("X-AUTH-IP");

        xlog("L_INFO", "$ci|log|X-AUTH-IP: $si");

        append_hf("X-AUTH-IP: $si\r\n");

        xlog("L_INFO", "$ci|log|provisional reply required in 2 seconds");

        $avp(s:final_reply_timer) = 2;

        t_on_reply("on_net_reply");

        t_on_failure("on_net_fault");
    }
    # if the request domain is not an IP or in our list of media servers then 
    # assume it is going somewhere outside our control and give that equipment
    # longer to respond.  Also arm a branch to log the replies
    else
    {
        xlog("L_INFO", "$ci|log|provisional reply required in 6 seconds");

        $avp(s:final_reply_timer) = 6;

        t_on_reply("off_net_reply");
    }

    # try to send the request on its way, if it fails send back a 
    # stateless error to the requestor
    if (t_relay())
    {
        xlog("L_INFO", "$ci|pass|$rd:$rp");
    }
    else
    {
        xlog("L_ERR", "$ci|end|unable to relay message");

        sl_reply_error();
    }

    exit;
}

route[nat_test_and_correct]
{
    # check if the request is from a client behind NAT, and fix if so...
    # this check looks at:
    # 1. if client has a private IP address (as defined by RFC1918) in the Contact field of the SIP message
    # 2. if client has contacted OpenSIPS from an address that is different from the one in the Via field
    if (client_nat_test("3")) 
    {
        xlog("L_INFO", "$ci|log|via address differs from source or RFC1918 address in contact");

        # adds the rport parameter to the first Via header
        force_rport();

        # will replace the IP and port in the Contact header with the IP and port 
        # the SIP message was received from
        fix_contact();
    }

    # if the request has a body see if it needs NAT corrections as well,
    # this check looks at:
    # 8. SDP is searched for occurrence of RFC1918 addresses  
    if (has_body("application/sdp") && nat_uac_test("8"))
    {
        xlog("L_INFO", "$ci|log|SDP contains a RFC1918 address");

        # alters the SDP information in order to facilitate NAT traversal.
        # 2. rewrite media IP address (c=) with source IP
        # 8. rewrite IP from origin description (o=) with source IP
        fix_nated_sdp("10");
    }
}

onreply_route[off_net_reply]
{
    # this branch handles replies that are comming from equipment
    # outside our control, just logging and NAT corrections
    xlog("L_INFO", "$ci|start|recieved off-net reply $rs $rr");
    xlog("L_INFO", "$ci|log|source $si:$sp");

    route("nat_test_and_correct");

    xlog("L_INFO", "$ci|pass|$(<request>si):$(<request>sp)");
}

onreply_route[on_net_reply]
{
    # this branch handles replies that are comming from our
    # media server, just logging and NAT corrections
    xlog("L_INFO", "$ci|start|recieved on-net reply $rs $rr");
    xlog("L_INFO", "$ci|log|source $si:$sp");

    route("nat_test_and_correct");

    # if one of our media servers has replied with a 407 or 401 associate
    # this call-id with that media server so the next "initial" requests
    # go to it (IE: the reply to the challenge)
    if (t_check_status("(407)|(401)") && $(si{ip.isip}) && ds_is_in_list("$si", "", "1"))
    {
        cache_store("local", "$ci", "sip:$si:$sp", 3600);

        xlog("L_INFO", "$ci|log|associated call-id with media server sip:$si:$sp");
    }

    xlog("L_INFO", "$ci|pass|$(<request>si):$(<request>sp)");
}

failure_route[on_net_fault]
{
    # if the failure cause was due to the transaction being
    # cancelled then we are complete
    if (t_was_cancelled()) 
    {
        xlog("L_INFO", "$ci|end|transaction was cancelled");

        exit;
    }

    # if the failure case was soemthing that we should recover
    # from then try to find a new media server
    if (t_check_status("(408)|(5[0-9][0-9])"))
    {
        xlog("L_INFO", "$ci|start|recieved or generated negative reply");
        xlog("L_INFO", "$ci|log|source $si:$sp");

        xlog("L_ERR", "$ci|log|moving media server $rd:$rp to probing mode");

        # flag the media server that failed and start sending SIP pings
        # when it begins responding put it back in the lsit
        ds_mark_dst("p");

        # ensure the endpoint is not locked to a failed server
        cache_remove("local", "$(ct.fields(uri){uri.user})");
        cache_remove("local", "$ci");

        # try to find a new media server to send the call to
        if(ds_next_domain())
        {
            xlog("L_INFO", "$ci|log|routing call to next media server $rd:$rp");

            # store the new callid association
            cache_store("local", "$ci", "sip:$rd:$rp", 3600);

            # if the request has a contact and is an INVITE then store the new
            # association
            if ($ct.fields(uri) && is_method("INVITE")) 
            {
                cache_store("local", "$(ct.fields(uri){uri.user})", "sip:$rd:$rp", 3600);

                xlog("L_INFO", "$ci|log|associated contact $(ct.fields(uri){uri.user}) with media server sip:$rd:$rp");
            }

            xlog("L_INFO", "$ci|pass|$rd:$rp");

            # reset the final reply timer
            $avp(s:final_reply_timer) = 2;

            t_on_reply("on_net_reply");

            t_on_failure("on_net_fault");

            # relay the request to the new media server        
            t_relay();
    
            exit();
        }
        else
        {
            xlog("L_ERR", "$ci|end|no other media servers avaliable");
        }
    }
}