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
>>>
>>>
>>
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