MGCP GW-FXS Registration Rejected on CCM 6.12!

Answered Question
Sep 19th, 2009

EVM-HD-8FXS/DID with EM0 8FXS and EM1 6FXO onboard in slot 1 on a 3845 router running IOS 12.(4)T.Did show diag on router OK. FXS programmed as a "POTS" on CCM.Running several ISDN PRI-T1's, no troubles there. Registration status on CCM is "Reject" Any ideas?

I have this problem too.
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Correct Answer by Nicholas Matthews about 7 years 2 months ago

Glad I could help.

Sometimes this is a problem with the TFTP service. Try resetting the gateway, 'no mgcp' 'mgcp' and resetting the TFTP service in CUCM. Sometimes if you use the 'tftp source' command you'll use an IP address CUCM can't reach.


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Brav3h3art Mon, 09/21/2009 - 09:35


I did a sh mgcp -

casndgbr#sh mgcp

MGCP Admin State ACTIVE, Oper State ACTIVE - Cause Code NONE

MGCP call-agent: 2427 Initial protocol service is MGCP 0.1

MGCP validate call-agent source-ipaddr DISABLED

MGCP validate domain name DISABLED

MGCP block-newcalls DISABLED

MGCP send SGCP RSIP: forced/restart/graceful/disconnected DISABLED

MGCP quarantine mode discard/step

MGCP quarantine of persistent events is ENABLED

MGCP dtmf-relay voip codec all mode out-of-band

MGCP dtmf-relay for voAAL2 is SDP controlled

MGCP voip modem passthrough mode: NSE, codec: g711ulaw, redundancy: DISABLED,

MGCP voaal2 modem passthrough disabled

MGCP voip modem relay: Disabled.

MGCP T.38 Named Signalling Event (NSE) response timer: 200

MGCP Network (IP/AAL2) Continuity Test timer: 200

MGCP 'RTP stream loss' timer disabled

MGCP request timeout 500

MGCP maximum exponential request timeout 4000

MGCP rtp unreachable timeout 1000 action notify

MGCP gateway port: 2427, MGCP maximum waiting delay 3000

MGCP restart delay 0, MGCP vad DISABLED


MGCP system resource check DISABLED

MGCP xpc-codec: DISABLED, MGCP persistent hookflash: DISABLED

MGCP persistent offhook: ENABLED, MGCP persistent onhook: DISABLED

MGCP piggyback msg ENABLED, MGCP endpoint offset DISABLED

MGCP simple-sdp ENABLED

MGCP undotted-notation DISABLED

MGCP codec type g711ulaw, MGCP packetization period 20

MGCP JB threshold lwm 30, MGCP JB threshold hwm 150

MGCP LAT threshold lwm 150, MGCP LAT threshold hwm 300

MGCP PL threshold lwm 1000, MGCP PL threshold hwm 10000

MGCP CL threshold lwm 1000, MGCP CL threshold hwm 10000

MGCP playout mode is adaptive 250, 100, 250 in msec

MGCP Fax Playout Buffer is 300 in msec

MGCP media (RTP) dscp: ef, MGCP signaling dscp: af31

MGCP default package: trunk-package

MGCP supported packages: gm-package dtmf-package trunk-package line-package

hs-package rtp-package atm-package ms-package dt-package

mo-package mt-package sst-package pre-package

MGCP Digit Map matching order: shortest match

SGCP Digit Map matching order: always left-to-right

MGCP VoAAL2 ignore-lco-codec DISABLED

MGCP T.38 Max Fax Rate is DEFAULT



MGCP T.38 Fax NSF Override is DISABLED

MGCP T.38 Fax Low Speed Redundancy: 0

MGCP T.38 Fax High Speed Redundancy: 0

MGCP control bound to interface Loopback0

MGCP media bound to interface Loopback0

MGCP Upspeed payload type for G711ulaw: 0, G711alaw: 8

MGCP Dynamic payload type for Cisco fax indication: 96, Cisco fax ack: 97

MGCP Static payload type for G.726-16K codec

MGCP Dynamic payload type for G.726-24K codec

MGCP Dynamic payload type for G.726-32K codec

MGCP Dynamic payload type for G.Clear codec

MGCP Dynamic payload type for NSE is 100

MGCP Dynamic payload type for NTE is 99

MGCP Guaranteed scheduler time is disabled

BTW - I have several voice PRI-T1 registered on router without issues..Any other ideas, its much appreciated


Brav3h3art Mon, 09/21/2009 - 12:54

Alright -

casndgbr#sh ccm | i Name

MGCP Domain Name:

That domain name matches up with the FXS on ports 2/0/0, 2/0/1, thru 15 as well as our voice ISDN PRI-T1's that are registered to the CUCM....What else can it be?

TIA - Thomas

Nicholas Matthews Mon, 09/21/2009 - 14:19

If you're registering a PRI:

controller t1 0/0/0

pri-group timeslot 1-24 service mgcp

interface Serial0/0/0:23

isdn bind-l2 ccm

If it's FXO/FXS:

dial-peer voice 999 pots

port 0/0/0

service mgcpapp

Other than that, check 'show voice port summary' and 'show voice call summary' to make sure the ports are in a good status. 'show isdn status' if it is a PRI should show 'multiple frame established'.

if your image contains _li it means you will need to include some other commands to get it to register because it's a lawful intercept image.


Brav3h3art Wed, 09/23/2009 - 07:02

OK - right after uploading the correct dial-peers into the router the FXS ports registered on CUCM!!

However, I have found some inconsistencies from CUCM to the routers, sometimes the dial-peers load from CUCM and sometimes they do not? Any ideas what to look for there or should I open a TAC case with Cisco...

Thanks for the help - Nick.

Correct Answer
Nicholas Matthews Wed, 09/23/2009 - 12:37

Glad I could help.

Sometimes this is a problem with the TFTP service. Try resetting the gateway, 'no mgcp' 'mgcp' and resetting the TFTP service in CUCM. Sometimes if you use the 'tftp source' command you'll use an IP address CUCM can't reach.


javin.craig Thu, 09/13/2012 - 11:24

Thanks for posting this nicholas, it was one of those things I spaced out when it stopped registering. 


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