From: Scott Morris (SMorris@xxxxxxxxxxxxx)
Date: Sat Dec 18 1999 - 17:46:03 GMT-3
This is a requirement within digital transmission lines (telephone
network systems). On a T-1 line, a 0 represents no voltage, no
pulse. With too many zeros in a row, the repeaters (or other
equipment) will lose count/timing because they've had no signal pulses
to count. There are different techniques to insert a 1 bit after
every consecutive chunk of seven 0's.
According to some FCC documents, with digital systems getting better
today, your lines can survive up to 40 consecutive 0's without doing
any damage, but most algorithms still work around the old 8-bit
rules.
Specific definition:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1915.htm
Many T-1 related links:
http://www.everythingt1.com/
Links about all sorts of things:
http://www.itprc.com/
Enjoy!
Scott Morris, MCSE, CNE (3.x), CCDP, CCIE #4713, Security
Specialization (CCIE)
-----Original Message-----
From: Khurram Khani [mailto:ajmal@emirates.net.ae]
Sent: Sunday, December 19, 1999 2:47 AM
To: ccielab@groupstudy.com
Subject: Question for knowledge
Hello.
Just came across one question...
What is 1 bit density in T1 lines?
Also I want to know about 4B/5B enconding technique, can any one
suggestion
me some Web bases resource.
Thanks
Khurram.
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:21:59 GMT-3