Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: [EFM] Re: OAM Transport Proposal




I assume that you are right regarding the definition of the full-duplex
repeaters.
There is no such definition in the 802.3 standards.
Practically there are two types of repeaters - as you mentioned:
1. A full duplex repeater - as per the 802.3 definition w/o the half duplex
limitation. 
   Generally this is implemented by two PHYs back to back with some MII data
transfer 
   capability. 
2. What you defined: a switch with/without the learning function disabled.
Basically 
   two MACs back to back.

I totally agree that we should better define the requirement. But this is a
reality that 
exists in huge numbers and as per service providers that use this solutions
a 
management capability is required. 

Now my main point is that with an auto-negotiation mechanism that will
contain the capability 
of only preamble. This will support whatevere definition we can provide for
the repeaters.
Then everythig is already there !!

Sergiu 

>>-----Original Message-----
>>From: Matt Squire [mailto:mattsquire@xxxxxxx]
>>Sent: Wednesday, April 24, 2002 2:54 PM
>>To: stds-802-3-efm@ieee.org; sergiu@nbase-xyplex.com
>>Subject: RE: [EFM] Re: OAM Transport Proposal
>>
>>
>>
>>We've had many threads on repeaters, media converters, 
>>regenerators, and
>>the like throughout the evolution of this work.  The following are my
>>recollections as reported by others (Geoff, Tony, etc.).  Pls correct
>>anything I misrepresent.  
>>
>>1) 802.3 defines half-duplex repeaters.  
>>2) 802.3 does not define full-duplex repeaters.
>>3) What some people commonly refer to as full duplex repeaters are
>>actually 2-port MAC frame forwarders (802.1D relays?).  
>>4) 802.3 does not define optical regenerators (ie protocol agnostic
>>signal regeneration).
>>5) 802.3 does not define media converters.  
>>
>>Since using the preamble to carry signaling is intended as a 
>>full-duplex
>>function only, I short-cut to the conclusion that preamble has no
>>applicability to any repeater, regenerator, or media converter as
>>defined by 802.3.  Before we could figure out how to address this
>>full-duplex repeater function that does not exist in 802.3, it would
>>have to be properly defined.  Thats all I was getting at.  
>>
>>People are concerned, people are thinking about it, but it has been
>>difficult to address because of the terminology confusion and our
>>scope.  
>>
>>- Matt 
>>
>>>
>>>Hi Matt and all,
>>>
>>>I will address only the issues related to 5) Regenerators and 
>>>converters.
>>>First of all I want to assume that we consider all the 802.3 
>>>interfaces, 
>>>including 100 Mbps and GbE. 
>>>
>>>802,3 defines the above entities. Look at 27. Repeater for 100 
>>>Mbps baseband
>>>networks. 
>>>The devices that we address are two port full duplex repeaters. 
>>>Also 802.3ab makes extensive references to repeater implementations. 
>>>
>>>And again, the moment that we defined any preamble based 
>>>capability - see
>>>page 9
>>>of the baseline presentation - we decided to make the 
>>>appropraite changes
>>>for preamble
>>>support. 
>>>
>>>I also had some questions, regarding packet based functionality. 
>>>This functionality I assume is not fully contained in the new 
>>>MAC (like the
>>>packet based
>>>flow control functionality). It requires an external processing unit
>>>(CPU+MAC, HW, or whatever).
>>>What is the level of service in the case of a busy link (even 
>>>malfunctioning
>>>due to a broadcast 
>>>storm, etc.)? Do we lose the management capacity for some time?
>>>Wouldn't an out-of-band mechanism (like preamble) be valuable 
>>>in order to
>>>provide even the 
>>>basic management information as defined in the suzuki proposal?
>>>
>>>I still think that the compromise should be a functional 
>>>compromise, that
>>>provide the 
>>>best of the two worlds meaning that the capabilities 
>>>negotiations should
>>>include four 
>>>options, and should be done also at the lowest level...
>>>
>>>Sergiu 
>>>
>>>
>>



The information contained in this electronic mail is privileged and
confidential, intended only for the use of the individual or entity named
above. If the reader of this message is not the intended recipient, you are
hereby notified that any dissemination, distribution, or copying of this
communication is strictly prohibited. If you receive this communication in
error, please immediately notify Disclaimer@xxxxxxxxxx Thank you.