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New Member

A question related to E1

Why does the corresponding serial interface of an E1 link show the default BW as 1984Kbit instead of the line data rate (=2048Kbit) or its actual data rate (64X30 = 1920Kbit) without framing and signaling ?

The confusion is that according to my understanding typical serial interface BW value is 1544Kbit irrespective of the link it is attached to.

Is interface BW value simply related to the number of time-slots allocated(in the context of E1)?


Re: A question related to E1


each B channel is 64K

Re: A question related to E1

First of all you need to check with your ISP whether the E1 link is Structured or unstructured.

Unstructured E1 will use all 32 timeslots (TS0 - TS31)for data ( 32x64 = 2048K)

However in case of structured E1, it uses 31 timeslots (TS1 - TS31) (31x64 = 1984K)

Re: A question related to E1

what u meant in stractured and non-stractured

i guess u mean inband and out of band signaling

inband use 32 channel out of band use 31 and the d channel will be dedcated for signalling!!


New Member

Re: A question related to E1


Theis may be even called as Framed and unframed CKTS

framed ckts/unframed CKTS - we get full 2048K Bandwidh ( When Using VWIC-1MFT-G703 or VWIC2-2MFT-G703 WAN Card)

if we use VWIC-1MFT-T1/E1 or VWIC2-2MFT-T1/E1 WAN Card) one time slot is used for Signalling and we get 1984Kbps only.


When changing the WAN card make sure that the service provider does the changes to get the link up.

New Member

Re: A question related to E1

Hi Srini,

Yes, G703 is meant for that and can get full 2048K.