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New Member

Clocking across leased T1

Hi,

I have two routers connected via serial point-to-point link; right now it works without any clocking commands, but gives

some CRC errors & carrier transitions -to overcome these problems,what is the recommended/best clockrate, and needs to be set on only one router?

Thanks

-Tennisman.

4 REPLIES
Purple

Re: Clocking across leased T1

Hello,

CRC errors are likely to mean that there are potential issues with line framing etc. Could you check that your framing is configured correctly, as per your carrier's instructions ? You can see this using 'show controller'...

Hope that helps - pls rate the post if it does.

Regards,

Paresh.

Purple

Re: Clocking across leased T1

One more thing.. clocking mis-configuration is likely to result in clock slips and not CRC errors so I don't think that is the issue..

However, ensure that your T1s at both ends are using the line as the clock source. Unless you are connecting them back-to-back (without going through a provider's network), configuring both to get clock from the line is fine.

Hope that helps - pls rate the post if it does.

Regards,

Paresh.

New Member

Re: Clocking across leased T1

What kind of routers do you have?

Are you using internal WIC-1DSU-T1, or do you have WIC-1T (or 2T) with external DSU?

New Member

Re: Clocking across leased T1

I was having the same issue, CRC, Input errors, and carrier transitions. Replacing the RJ45 cable to the smart jack from one of the router's seems to have corrected it. I also made sure one of the routers was set to clock source internal

config-if#service-mod t1 clock source internal

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