Using SIP RTP CoS mark 5
       > 0x9605d10 -- Strict RTP learning after remote address set to: 178.45.249.116:28072
[Feb 26 12:06:55] NOTICE[1567][C-00000596]: chan_sip.c:6843 update_call_counter: Call from peer '2201' rejected due to usage limit of 1
[Feb 26 12:06:55] NOTICE[1567][C-00000596]: chan_sip.c:26403 handle_request_invite: Failed to place call for device 2201, too many calls




extensions.conf
[in_rt]
exten => 2201,1,Goto(ringroups-custom-3,s,1)
exten => 2202,1,Goto(ringroups-custom-3,s,1)
exten => 2203,1,Goto(ringroups-custom-3,s,1)

[ringroups-custom-3]
exten => s,1,NoOp(line3)
exten => s,n,MixMonitor(/mnt/sdb1/records/${CALLERID(num)}_${EXTEN}_${STRFTIME(${EPOCH},MSK-3,%Y%m%d-%H%M%S)}.wav,b)
exten => s,n,Dial(SIP/100&SIP/317&SIP/318,10,itT)



sip.conf
register => 2201:XXXXX@285110.17.rt.ru/2201
register => 2202:XXXXX@285110.17.rt.ru/2202

[rt](!)
type=friend
qualify=300
canreinvite = no
insecure=port,invite
host=285110.17.rt.ru
fromdomain=285110.17.rt.ru
dtmfmode=rfc2833
disallow=all
allow=alaw
call-limit=1
registersip=yes

[2201](rt)
username=2201
defaultuser=2201
secret=XXXXX
fromuser=2201
context=2201

[2202](rt)
username=2202
defaultuser=2202
secret=XXXXXX
fromuser=2202
context=2202