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New Member

E3 strange behaviour


I have an E3 line that i have started to test, but it seems to be impossible to make it work, here is the config:

interface Serial1/1/0

ip address x.x.x.x

no ip route-cache distributed

framing g751

dsu bandwidth 34010

(I have tried to get clock source from internal or line with the same result)

The encapsulation is HDLC with CRC16.

The problem is that the interface is up, but line protocol is down. And sometimes along 10 or 20 seconds line protocol comes up(i can ping the other side!) but after that time lapso line protocol comes down again. The line´s carrier says that in his side everything is fine.

Any idea?, thanks in advance :)

New Member

Re: E3 strange behaviour

I can't say that I have any experience with E3, as I'm in the States. But based on my experience with carriers over here, it's their problem. Are you taking errors on the interface?

New Member

Re: E3 strange behaviour

The only alarm is (after doing un sh controllers serial x/X/X):

"Receiver has remote alarm."

kind regards


Re: E3 strange behaviour

Hi there,

I dont know about routers, but based on my knowledge about the DSU configuration in my card I'm explaining this.

The problem could be due to the DSU setting. Depending on the DSU type you are using, the E3 framing could change. A standard E3 frame has 12 overhead bits and 1524 data bits (may also be called as clear mode)

If you are using it Digital link DSU DL3100E mode, then the E3 frame could be set as 16 overhead bits and 1520 data bits. If you set the line to some subrate (i.e less than 34.368), then the number of data bits would vary.

If you are using it ADC Kentrox mode, then the E3 frame would have 12 overhead bits and the number of data bits would depend on the subrate you use.

If you use the fullrate, then it same as the clear mode i.e 12 ovh bits and 1524 data bits. So, if the other end is not using any DSU, then try using the clear mode.

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