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[EFM] OAM - To side-band or not to side-band

Roy -

Managed Ethernet repeaters (more commonly known as hubs these days) have 
been around for some while, and they use MAC frames to carry their (SNMP) 
management exchanges. I would therefore hesitate to use that particular 
argument either for or against the use of a side-band for OAM.

Having said that, in networks with repeaters there may be distinct 
advantages in *not* using such a side-band for OAM - for example, where it 
is the device the other side of the repeater that you want to manage. 
Unless, of course, you start putting some form of addressing into this 
PHY-based side channel, which rapidly starts to look like you're 
replicating MAC functionality in the PHY, which begins to look like a waste 
of time & effort.

As to T1 and T3, there's no doubt that some of the EFM participants (myself 
for one) are not intimately acquainted with the management entrails of 
these technologies, and with the thinking behind why they are that way. I'm 
sure that some of that information may be useful in informing what we do in 
EFM.  However, I'm equally sure that re-inventing T1 or T3, giving it a 
bit-rate that is a power of 10, & then badging it "Ethernet", would be a 
total waste of our time.  After all, if you continue to do what you have 
always done, you inevitably end up with what you have always had.


At 11:31 26/09/2001 -0500, Roy Bynum wrote:
>There are a lot of other reasons to have the OAM ou-of-band to the MAC 
>traffic, such as being able to support OAM on an intelligent "transparent" 
>full duplex repeater in the future.  When this group took on the task of 
>adding subscription network support for edge access infrastructure into 
>Ethernet, they took on applying most all of the functionality that is 
>being used today.  There is a long history of why the functionality for 
>these types of services is what it is.  How many of the EFM Task Force 
>people have looked at how the OAM overhead of T1 or T3 framing works 
>today?  How many of the EFM Task Force people have looked into why the OAM 
>overhead of T1 or T3 framing works the way that it does?