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Hi all,

I have an issue with multiple MFT E1 G703 cards which are all PPP
multilinked.
I'm seeing clock slip on the controllers and I suspect the clocking
must be incorrect.
CCO is not much help for this type of configuration but my thoughts are
all the cards need to be clocked from the same source, or is it OK that
they can all be clocked separately (end to end pairs)?
Config at present :-

A end:
no network-clock-participate slot 1
no network-clock-participate slot 2
no network-clock-participate wic 0
no network-clock-participate wic 1
!
controller E1 0/0 (Same for all controllers 0/1-3 1/0-3 2/0-3)
clock source internal
channel-group 0 unframed
!

B end:
no network-clock-participate slot 1
no network-clock-participate slot 2
no network-clock-participate wic 0
no network-clock-participate wic 1
!
controller E1 0/0 (Same for all controllers 0/1-3 1/0-3 2/0-3)
channel-group 0 unframed
!
My thoughts are that at the 'internal' end they should all sync to the
same clock source, be that any of the cards. So how do I set up the
network clock select/participate commands.
Anyone done this scenario and got it working OK?

Happy new Year to the group
Bob

I don't really understand this myself however
since there have been no other
responses I will put in my 2p worth and ask
my own question after.

I assume that in this situation
you use the default of "clock source line" on the controller
on both sides but I am not sure. I think that unless
you have specially asked the telco to disable clocking
that they will do it for you.

However:-

I am presently puzzling over something similar myself.

MFT T1 as PRI installed in 0/0//0 (wic 0)

network-clock-participate wic 0
no network-clock-participate aim 0
no network-clock-participate aim 1

controller T1 0/0/0
framing esf
linecode b8zs
pri-group timeslots 1-24 service mgcp


interface Serial0/0/0:23
no ip address
isdn switch-type primary-5ess
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable

vgw1#sh netw
Network Clock Configuration
---------------------------
Priority Clock Source Clock State Clock Type
10 Backplane GOOD PLL

Current Primary Clock Source
---------------------------
Priority Clock Source Clock State Clock Type
10 Backplane GOOD PLL


My best guess is that this extra clocking stuff
(over Plain Old Clocking) is all to do with
the Drop and Insert (DI) feature which allows T/E1
channels to be directly 'Copied' between trunks.
In that case all participating trunks need to use
the same clock source.

Maybe you don't need to use it for ordinary data
use of T/E1s.

So my question is:-
should I have a

network-clock-select 1 T1 0/0/0

statement.

We have only the single T1 and use is as a PRI
as can be seen above.

Maybe I will do a TAC case after the break.

Hi,
I seem to remember reading on CCO that they recommend you specify the
clock source even though I think it defaults to the card anyway.
As I've said I find the descriptions on CCO somewhat lacking.
In my case, because it's G703, one end clocks the other but with three
dual cards I'm not sure if multiple clocks are causing the issue.

Happy New Year
Bob