Re: what's channellized E1?

[Yu Ning <yuning () mindless com>]

Hi,

Jan Czmok wrote:
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>
> On 18-Sep-98 Yu Ning wrote:
> > Hi friends,
> >
> > A very very basic question:
> > What does "channellized E1" mean? What's its difference from a "normal"
> > E1 connection?
> >
> > reply to my mail box, if you think such message is too basic posting
> > on nanog, thanks.
> >
> > regards,
> >
> > Yu Ning
> > --
> > ___________________________________________*
> >
> > Yu Ning
> > ATM R&D Centre of
> > BUPT (Beijing U. of Posts&Telecom)
> > Beijing (ZIP:100876, MBox:147#), P.R.China
> > Ideas ONLY reflect my own views,:-)
> > ___________________________________________
>
> Hi all!
>
> Okay a bit clearing about E1:
>
> E1 is Linespeed 1984 or 2048.
>
> Unchannelized E1 means clear bandwidth of 2048 unstructured
> channelized e1 means trunk is divided by 32 Timeslots; Timeslot 0 is used for
> syncronization of the other timeslots and cannot be used for data transmissions.

Then you mean unchannelized E1 is clear channel of 2M with no framing
convention of PDH. While channelized E1 is the normal E1 of PDH with 
slot 0 for synchronization, and slot 16 for in-band signaling. Then 
if I order a channelized E1, I actually get only 30 slots available 
for my data, right?

The practical example may be: if I rent a 2M DDN p-t-p connection form
A to B, then I get the _unchannelized_ E1 connection, clear bandwidth,
and low delay. While the 2M connection between LE(local exchange in
PSTN)
A and LE B of a carrier is _channelized_ E1 connection with possible 
30 slot in it for 64K voice, right?

What's more, what's fractional E1 mean? Only nx64K(n<32) connection 
within a _channelized_ E1?


> e.g.: unchannelized e1 is "point-to-point" but
> channelized e1 can mean "point-to-multipoint"
Your "point-to-multipoint" mean the slots can be swtiched to different
termination, because they are actually a "bundle" of connections,right?


thanks for your commnets.

Yu Ning
> Hope that clear it a bit
>
> Jan Czmok
>
> - ---
> Jan Czmok
> Senior Network Engineer
> IPF.NET Service Provider GmbH
>
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-- 
___________________________________________*

Yu Ning
ATM R&D Centre of
BUPT (Beijing U. of Posts&Telecom)
Beijing (ZIP:100876, MBox:147#), P.R.China 
Ideas ONLY reflect my own views,:-)
___________________________________________