Clock Source for PRI Emulation

[Douglas Oman]

I am trying to hand off a PRI to a Mitel phone system and I am having issues with Slips. This is the first time I have done it on the 4321 but I have accomplished this many times on 2800 & 2900's. The issue here is in the controller I am unable to set the clock source to internal while at the same time setting it as a PRI. 

In the past my controller config looked like this:

controller T1 0/1/0
framing esf

clock source internal
linecode b8zs
cablelength short 110
pri-group timeslots 1-24

But on this 4321 I get an error when I try to set the PRI group with the clock source set to internal

%Cannot create ds0/tdm/pri-group with clock source internal
%pri-group voice-dsp cannot be created under the clock source configuration

Has anyone ever done this with a 4321 or have any ideas?

Here is the configuration without the clock source internal set. Also, I should mention that the network-clock sync is set to auto.

controller T1 0/1/0
framing esf
linecode b8zs
cablelength short 110
pri-group timeslots 1-24
description PRI to Phone System
!

interface Serial0/1/0:23
no ip address
encapsulation hdlc
isdn switch-type primary-ni
isdn protocol-emulate network
isdn incoming-voice voice
isdn supp-service name calling
isdn bchan-number-order ascending round-robin

!

voice-port 0/1/0:23
translation-profile incoming prefix
echo-cancel erl worst-case 0
echo-cancel mode 2
no vad

[Douglas Oman]

I'm just getting back to this project. Wanted to give it a bump in case anyone has information.

[Ritesh Desai]

Hey Hi,

Can you elaborate what you are trying to achieve...

[Douglas Oman]

I apologize but I'm not sure how I can elaborate any more than I already have in my very first post. Is there something more specific details you're looking for?

[Ritesh Desai]

Hey Hi Douglas,

I asked to elaborate basis your comment. I went through your 1st post and I too had same issues with me on ISR 4000 series router. I am based in India so we have E1 channel signalling.

Most probably the PRI SLIP errors are possibly with network time.

Try looking at this document URL https://www.cisco.com/c/en/us/td/docs/routers/access/interfaces/NIM/software/configuration/guide/4gen-t1-e1-nim-guide.html

and refer title sections
“Network Synchronization for the Cisco 4000 Series ISRs”

and
“Configuring Cisco Fourth-Generation T1/E1 Voice and WAN Network Interface Module”

I added 2 commands on my ISR 4331

#Network clock synchronisation auto
#Network clock input source

This fixed SLIP errors on E1 controller PRI interface. This helped me fixing call drop issues as well. on my side TATA Telecom provider did thorough check and confirmed there is no issue from there end.

After adding the commands, execute command #clear counters which will clear slips error counts on E1/T1 interface and will help to monitor slips errors still arising.

I hope this fixes it.

[Douglas Oman]

Ritesh, 

Thank you for the reply, but in this case we are emulating the network to the phone system thus we have to be the clock source not the other way around. I do understand what you're saying but sadly in this case is not the solution. As stated above on the older 2800 and 2900 series ISRs I can set clock source internal which is what I want to do but the 4300 is giving me the error mentioned above

[Ritesh Desai]

Hey Hi Douglas,

Refer to same URL as shared above with Title section:Configuring Cisco Fourth-Generation T1/E1 Voice and WAN Network Interface Module. Refer to Configuring the T1/E1 Network Interface Module for Data Support. Document mentions. 

Specifies the clock source. The options are as follows:

internal—Sets the controller framer as the clock master.

The clock source internal command is only applicable with the channel-group command and the pri-group (for data) command.

Note: The pri-group command is supported on the NIM-xCE1T1-PRI for data without the keyword voice-dsp.

Can you check by doing this? Please try...

[Douglas Oman]

Ritesh,

 I did read that document. The issue is this is a PRI voice circuit without Data. I am not sure now how to accomplish this without being able to set the clock source to internal. I can't imagine that Cisco has removed this type of support as they still allow the isdn protocol-emulate network under the serial interface.

[abyewondimu]

The clocking command has changed with the ISR 4XXX Routers. Look at the posting below.

https://amyengineer.com/2016/10/21/bye-bye-2800s/#comments