RE: slight offtopic: Cat4000: Interface Symbol-Err?

From: David Hiers (David_Hiers@adp.com)
Date: Wed Dec 03 2003 - 11:28:14 GMT-3


Symbols are pretty low level things. From the IEEE 802.3 2000 spec:

symbol: Within IEEE 802.3, the smallest unit of data transmission on the medium. Symbols are
unique to the coding system employed. 100BASE-T4 uses ternary symbols; 10BASE-T uses Manchester
symbols; 100BASE-X uses binary symbols or code bits; 100BASE-T2 and 1000BASE-T uses quinary
symbols.

It goes on to be of even more "help":

Manchester encoding is used for the transmission of data across the AUI. Manchester encoding is a binary
signaling mechanism that combines data and clock into "bit-symbols." Each bit-symbol is split into two
halves with the second half containing the binary inverse of the first half; a transition always occurs in the
middle of each bit-symbol. During the first half of the bit-symbol, the encoded signal is the logical complement
of the bit value being encoded. During the second half of the bit-symbol, the encoded signal is the
uncomplemented value of the bit being encoded.

David

********************************************
David Hiers
CCIE, CISSP
ADP Dealer Services
2525 SW First Avenue
Portland, OR 97201

v: 503 402 3703
email: david_hiers@adp.com
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-----Original Message-----
From: Oliver Ziltener [mailto:ziltener@netcloud.ch]
Sent: Wednesday, December 03, 2003 1:24 AM
To: ccielab@groupstudy.com
Subject: slight offtopic: Cat4000: Interface Symbol-Err?

Hello

does anyone knows what is the meaning of Symbol-Err?
I didn't find any good document on the cco!

This is an printout form the cco.
4507#show interfaces GigabitEthernet 1/1 counters errors

Port CrcAlign-Err Dropped-Bad-Pkts Collisions Symbol-Err
Gi1/1 0 0 0 0

Port Undersize Oversize Fragments Jabbers
Gi1/1 0 0 0 0

Port Single-Col Multi-Col Late-Col Excess-Col
Gi1/1 0 0 0 0

Port Deferred-Col False-Car Carri-Sen Sequence-Err
Gi1/1 0 0 0 0

thanks
Oliver



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