RE: [802.3ae] Link Fault Signalling
I would appreciate it, if someone would confirm
if the link fault signalling mechanism described
in the attached message is correct.
Burt S, Christian.
Tel : (613)599-5797
Fax : (613)599-1247
> -----Original Message-----
> From: Burt Christian
> Sent: Wednesday, December 05, 2001 8:38 PM
> To: 'Grow, Bob'; HSSG (E-mail)
> Cc: 'pat_thaler@xxxxxxxxxxx'
> Subject: RE: [802.3ae] Link Fault Signalling
> Thanks for the replies. My understanding now is as follows:
> 1. If a fault is detected on the receive path, at the PMD or
> the PMA, Local Fault Ordered Sets (LFOS) will be transmitted
> by the PCS to the RS. Consequently, the RS will send Remote
> Fault Ordered Sets (RFOS) to the PCS.
> 2. If a fault is detected on the transmit path at any sublayer
> including MAC, RS, PCS, PMA or PMD on the transmit path,
> LFOS will be generated and transmitted by the PCS to the PMA.
> (Although if a fault is detected on the transmit path at PCS,
> PMA or PMD, it cannot be guaranteed that the LFOS would be
> generated by the PCS and if they are, whether they will get
> through the PMA or PMD.)
> Burt S, Christian.
> Ceyba Inc.,
> Systems Specialist
> Tel : (613)599-5797
> Fax : (613)599-1247
> burt@xxxxxxxxx www.ceyba.com
> > -----Original Message-----
> > From: Grow, Bob [mailto:bob.grow@xxxxxxxxx]
> > Sent: Wednesday, December 05, 2001 7:51 PM
> > To: Burt Christian; HSSG (E-mail)
> > Subject: RE: [802.3ae] Link Fault Signalling
> > The RS only forces the transmit path to Remote Fault or Idle.
> > It never
> > generates Local Fault. The PCS only forces the data path to
> > Local Fault
> > (whether toward the RS or toward the fiber). At a RS receive
> > (i.e., the
> > link fault state machine), reception of Local Fault causes
> > the transmit path
> > RS to force Remote Fault; and reception of Remote Fault
> > causes the transmit
> > path RS to force Idle.
> > --Bob Grow
> > -----Original Message-----
> > From: Burt Christian [mailto:burt@xxxxxxxxx]
> > Sent: Tuesday, December 04, 2001 7:07 PM
> > To: HSSG (E-mail)
> > Subject: [802.3ae] Link Fault Signalling
> > Hi,
> > I wanted to ensure that my understanding of the RS Link Fault
> > Signalling mechanism is correct. I am trying to understand the
> > mechanism rather than the details of the protocol. If someone
> > can please confirm the following description to be correct, I
> > would appreciate it.
> > 1. If a fault on either the transmit path or the receive path
> > of PMD or PMA is detected then regardless of the quality of
> > the signal received by the PCS on the receive path, Local
> > Fault Ordered Sets will be transmitted by the PCS to the RS.
> > 2. Once the RS Link Fault Signalling State Machine (Figure 46-9)
> > has entered the FAULT state with link_fault == Local Fault, RS
> > will start transmiting Remote Fault Ordered Sets on the transmit
> > path.
> > One thing I would like to confirm is that the Local Fault Ordered
> > Set will never be transmitted by the RS on the link where the link
> > is defined as the communication channel between two RS peers. This
> > is quite clear based on the very last section of 220.127.116.11 but I
> > would like to ensure that I am not missing anything.
> > Thank you.
> > Burt S, Christian.
> > Ceyba Inc.,
> > Systems Specialist
> > Tel : (613)599-5797
> > Fax : (613)599-1247
> > burt@xxxxxxxxx www.ceyba.com