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New Member

[SOLVED] Instant ringback when using sip trunk to SP

Hi all,

 

We use CUCM 8.0.2.

We have a SIP trunk to a SP connected via one of our Cisco 2911 routers configured as a CUBE.

Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.0(1)M3, RELEASE SOFTWARE (fc2)

c2900-universalk9-mz.SPA.150-1.M3.bin

Cisco CISCO2911/K9 (revision 1.0)

 

Technology Package License Information for Module:'c2900'

----------------------------------------------------------------

Technology Technology-package

                  Current       Type

-----------------------------------------------------------------

ipbase        ipbasek9      Permanent

security      securityk9    Permanent

uc              uck9            Permanent

data           None            None

 

 

We also have several ISDN lines that run out via various Cisco routers configured as H323 gateways.

We use 7945 and CIPC for our phones.

 

We're having an issue with calls going via the SIP trunk where we hear ringing instantly after dialling - but before the actual device at the other end starts ringing (considerable difference).

 

Using the SIP trunk: If I make a call to my mobile phone - I hear ringing instantly - about 3 rings before my mobile phone actually starts ringing - undesireable.

Using H323 gateway: If I make a call to my mobile phone - I hear silence for a bit - then ringing when the mobile starts ringing - desired.

 

Using SIP trunk: If I make a call to a landline that is ready - it rings instantly for at least 1 ring - before the actual phone I'm calling starts ringing - undesireable.

Using H323 gateway: There is a momentary pause before hearing ringing on my phone and the phone I dialled - desired.

 

Using SIP trunk: If I make a call to a landline that is off-hook (with no call-waiting/etc.) - it rings once and then returns the busy signal (the worst issue) - undesireable.

Using H323 gateway: There is a momentary pause before hearing busy signal - desired.

 

Phone to phone internally (same network): Operates as expected (instantly rings locally and on the phone I'm calling). Between phones that utilise the SIP trunk and phones that utilise the H323 gateways within the same network - communication is instant and as expected.

 

Any ideas why this happens and how to stop it?

I want it to not ring until the situation is known and that it can provide the appropriate feedback (ringing/busy/etc.).

 

Some possibly relevant config (note that there is a known bug with this IOS that meant I had to declare the codec in each dial-peer as the voice class would not work):

voice service voip

address-hiding

mode border-element

allow-connections sip to sip

sip

  bind control source-interface GigabitEthernet0/0

  bind media source-interface GigabitEthernet0/0

  header-passing error-passthru

  early-offer forced

  midcall-signaling passthru

 

interface GigabitEthernet0/0

ip address x.x.x.x 255.255.255.252

ip access-group acl.SIP-IN in

no ip redirects

no ip unreachables

ip verify unicast reverse-path

ip virtual-reassembly

duplex full

speed 100

no cdp enable

 

gateway

timer receive-rtp 1200

!

sip-ua

connection-reuse

 

gatekeeper

shutdown

 

dial-peer voice 1 voip

description *** INBOUND CALLS FROM CARRIER ***

translation-profile incoming SIPTRUNK-INCOMING

session protocol sipv2

incoming called-number #blah blah#

dtmf-relay rtp-nte

codec g711alaw

ip qos dscp cs5 media

no vad

 

dial-peer voice 61 voip

description **** WA, SA AND NT NUMBERS ****

destination-pattern 0[8]........

session protocol sipv2

session target ipv4:<MY SP's SIP SERVER>

incoming called-number 0[8]........

dtmf-relay rtp-nte

codec g711alaw

ip qos dscp cs5 media

no vad

 

dial-peer voice 81 voip

description **** MOBILE NUMBERS ****

destination-pattern 0[4]........

session protocol sipv2

session target ipv4:<MY SP's SIP SERVER>

incoming called-number 0[4]........

dtmf-relay rtp-nte

codec g711alaw

ip qos dscp cs5 media

no vad

 

dial-peer voice 500 voip

description *** INBOUND SIP TRUNK TO CUCM PUB ***

translation-profile outgoing SIPTRUNK-CALLING-ADD-0

preference 1

destination-pattern 5[12]..

session protocol sipv2

session target ipv4:<OUR CUCM PUBLISHER IP>

dtmf-relay rtp-nte

codec g711alaw

ip qos dscp cs5 media

no vad

 

 

Any help or a point in the right direction would be greatly appreciated.

 

Cheers,

Brett

  • IP Telephony
2 REPLIES
New Member

I ended up resolving this

I ended up resolving this issue as follows:

 

In CUCM, under Device > Device Settings > SIP Profile.

I modifed the profile relevant to my SIP trunk, under the "Trunk Specific Configuration", I set "SIP Rel1XX Options" from "Disabled" to "Send PRACK if 1xx Contains SDP".

Now, I get the expected delay before hearing ringback.

 

Solved!

This resolved the instant

This resolved the instant ring back issue for Level3 SIP as well :).

 

Thanks. 

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