Header Only - DO NOT REMOVE - Extreme Networks

Definitions of the different configurable forms of pause


Userlevel 3
Article ID: 6835

Products
DFE
Matrix C1

Standards
802.3x

Goals
Pause definitions
Flow control options

Cause
Here are the configurable port advertisement modes:
Matrix N3 Platinum(su)->set port advertise fe.1.1 ?
10t 10BASE-T half duplex mode
10tfd 10BASE-T full duplex mode
100tx 100BASE-TX half duplex mode
100txfd 100BASE-TX full duplex mode
1000x 1000BASE-X, -LX, -SX, -CX half duplex mode
1000xfd 1000BASE-X, -LX, -SX, -CX full duplex mode
1000t 1000BASE-T half duplex mode
1000tfd 1000BASE-T full duplex mode
pause PAUSE for full-duplex links
apause Asymmetric PAUSE for full-duplex links
spause Symmetric PAUSE for full-duplex links
bpause Asymmetric and Symmetric PAUSE for full-duplex links[/code]
The descriptions as given are correct, but do not provide sufficient detail to provide a reasonable guide as to their use.

Solution
Here is a more detailed explanation of the pause types:
none - Bit state is not applicable.
No flow control is active.
pause - (symmetric) Pause bit is on. There is no Asymmetric Pause bit.
The node can transmit and receive 10/100 flow control requests.
This is compatible with a pause (=symmetric 10/100) peer.
apause - (asummetric) Symmetric Pause bit is off, Asymmetric Pause bit is on.
The node can transmit gigabit flow control requests but
cannot receive them.
This is compatible with a bpause (=both) peer.
spause - (symmetric) Symmetric Pause bit is on, Asymmetric Pause bit is off.
The node can both transmit and receive gigabit flow control
requests.
This is compatible with a spause (=symmetric) or bpause
(=both) peer.
bpause - (both) Symmetric Pause bit is on, Asymmetric Pause bit is on.
The node can both transmit and receive gigabit flow control
requests.
This is compatible with a apause (=asymmetric) or spause
(=symmetric) or bpause (=both) peer.[/code]
Here are all the possible combinations of local and remote peer advertisements, and the expected flow control state resulting from each combination:
Local Remote Resulting
** Advertisement ** Flow Control

none none None
none pause None
none apause None
none spause None
none bpause None

pause pause Possibly pause local or peer 10/100 transmissions
pause apause None
pause spause None
pause bpause None

apause apause None
apause spause None
apause bpause Possibly pause peer gigabit transmissions

spause spause Possibly pause local or peer gigabit transmissions
spause bpause Possibly pause local or peer gigabit transmissions

bpause bpause Possibly pause local or peer gigabit transmissions[/code]

0 replies

Be the first to reply!

Reply