Showing results for 
Search instead for 
Did you mean: 

Problem with the clock

Level 1
Level 1

I have a problem with the clock source.

in this situation is the router giving the clock to the


im receiving this error from the router

Feb 22 10:56:08.626 GMT: BRI1/0: !!!CHECK CLOCK SOURCE!!! and the interface is disabled due to Lost framing count of 41 in the past

and the router shutdown the bri .

this is the configuration from the bri

interface BRI1/0

description Ligacao ISDN ao PBX

no ip address

no ip mroute-cache

isdn switch-type basic-net3

isdn overlap-receiving

isdn protocol-emulate network

isdn layer1-emulate network

isdn incoming-voice voice

no isdn T309-enable

isdn send-alerting

isdn sending-complete

no isdn outgoing display-ie

isdn static-tei 0

isdn skipsend-idverify


Anyone with a tip?


Hugo bejinha

3 Replies 3

Aaron Harrison
VIP Alumni
VIP Alumni

Hi Hugo

Have a look at this document:

On the bottom of page four it says:

Cisco IOS currently only supports layer 2/3 network side operation with QSIG, NET3 and NI ISDN

switch types.

Since you are using NET3, it looks like the Cisco card won't provide clocking (Layer 1) - can you have your Alcatel provide this? Or use a different ISDN switch type setting?


Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Hi Aaron,

First thx for the fast help.

I looked the document but in the document isnt talking anything about layer1 :(.

the card from the alcatel must be in slave mode because is the same card that is connected to the public PBX.


Hugo Béjinha

Level 1
Level 1

I have the same problem on c3725, c3640, c2600xm models. Older versions of IOS worked fine on model c2600xm (12-2-16 or 17 IPPlusIPsecDES). We tried to change the gender (in a lab) and the clock timing looked stable.