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New Member

every call is being dropped on the 5th minute

Hi to all

Here is the problem

I have 2811 connected through WVIC-MFT-E1 to the telco using ISDN PRI service.

IPT using CCM 4.2.

Every call I made out and in to the PSTN gets dropped on the exactly 5th minute (300 sec) with cause code 127 interworking error

18F1 : 14740 882840880ms.14758 +160 +300900 pid:200 Answer 08070707#

dur 00:05:00 tx:14802/2486736 rx:14987/2397920 7F (interworking (127))

Telephony 3/0 (14740) [3/0] tx:278170/278170/0ms g711alaw noise:-67dBm acom:-29dBm

18F1 : 14742 882840950ms.14759 +90 +302820 pid:3334 Originate 600

dur 00:05:02 tx:14860/2377600 rx:14804/2368640 7F (interworking (127))

IP SRTP: off rtt:0ms pl:277790/0ms lost:0/2/0 delay:55/55/65ms g711alaw

media inactive detected:n media contrl rcvd:n/a timestamp:n/a

I get slips on the line:

R2811-B#sh controllers e1 0/0/0

E1 0/0/0 is up.

Applique type is Channelized E1 - balanced

Description: BTC_PRI_LINE

No alarms detected.

alarm-trigger is not set

Version info Firmware: 20051006, FPGA: 20, spm_count = 0

Framing is CRC4, Line Code is HDB3, Clock Source is Line.

CRC Threshold is 320. Reported from firmware is 320.

Data in current interval (788 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

8 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

8 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

And here is the configuration:

controller E1 0/0/0

linecoding hdb3

framing crc4

clock source line

pri-group timeslots 1-31

interface Serial0/0/0:15

no ip address

encapsulation hdlc

isdn switch-type primary-net5

isdn overlap-receiving

isdn incoming-voice voice

isdn send-alerting

isdn bchan-number-order ascending round-robin

no cdp enable


The telco said that this is not their problem.

Any suggestion might be useful.

Thanks in advance

New Member

Re: every call is being dropped on the 5th minute


Can you post "debug isdn q921" and "debug isdn q931" for a call?


Re: every call is being dropped on the 5th minute

As suggested, post a Q.931 debug output here.

It is important to know which side drops the call with DC 127.

Might be the, CCM is sending some QSIG-ed facility to the gateway which is then transmitted to the ISDN link.

New Member

Re: every call is being dropped on the 5th minute

Hi to all,

I found the problem ? there is a pix between the call manager and phones network, and the gateway.This f? device was droping the udp connection after exactly 5 minutes because it is considering it as idle ? why? I don?t know

Thanks for the help to all that responded ? sorry I cant send debugs now because I obviously didn?t save any.

Have a great evening/day