From: kasturi cisco (kasturi_cisco@hotmail.com)
Date: Thu Mar 25 2004 - 15:51:11 GMT-3
Hi,
This is how i understand it.Someone can add and correct me if needed.
In E1 operation you can configure each E1 port as one or more interfaces
for framed (channelized) operation called channelized E1 for example like
256Kbps or 512 Kbps, or as a single channel for unframed (unchannelized)
operation. So wherever u hav use for Channelized E1 u would use framed
config.
http://www.cisco.com/warp/public/cc/pd/ifaa/pa/much/prodlit/portm_ds.htm
For more info this is how it works.
The E1 interface is divided into 32 time slots or frames. Each of the 32
time slots is an 8-bit frame that transmits data at 64 kbps. Each of
these time slots can be configured to carry data or to remain empty. The
E1 port adapter inserts an idle pattern into empty time slots.
Time slot 0, or the first 8 bits is reserved as overhead. The remaining
248 bits (31 frames with 8 bits each) are designated time slots 1 through
31. Time slot 16 is also designated as a framing slot when using framed
mode. When you use unframed mode (G.703)the default, you can configure
time slot 16 to carry data and operate as any of the other slots.
Therefore in framed mode time slot 0 must be designated as a framing
signal time slot 16 can be configured for either data or framing.
Unframed mode uses all 32 time slots for data/payload. None of the 32
time slots are used for framing signals. This allows each of the 32 time
slots to transmit at 64 kilobits per second.Example is 32 time slots x 64
kbps = 2.048 Mbps.
Framed mode (G.704) allows you to specify a bandwidth for the interface
by designating a number of the 32 time slots for data, and reserves
others for framing (timing). When you use framed mode you must designate
start and stop time slots,the slots within these boundries are used for
data, and the remaining slots are left idle.
For e.g on an interface with framing set on time slots 1 through 8, the
interface will carry data within the specified 8 frames, and frames 9
through 31 will remain idle. Because each time slot transmits at 64 kbps,
the interface will operate at 512 kbps (8 frames x 64 kbps = 512 kbps).
Hope that helps.
Good Luck,
Kasturi.
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