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RE: [EFM] OAM developing Geoff's observation.

Hi Bob,

I think following issues for OAM in EFM to decide in-band or side-band OAM support.

1. What needs to be done for OAM in 802.3ah? Influences in-band or side-band decision?

2. How OAM is done?
Since, 802.3ah has extension EFM (etherenet in first mile), with that there seems to be two choices:
   a) Both layer 1 and layer 2 are Ethernet, or
   b) layer 1 does not have to be Ethernet, but layer 2 is Ethernet.

In case a) there are further couple of choices:
i)  All the existing Ethernet PHYs and any new 802.3 PHY MUST be supported.
ii) A new EFM phy will be developed and MUST be supported, and support for any 
    802.3 Ethernet PHY is optional.

If only a) and ii) are the objectives then either in-band or side-band can achieve the 
objective with side-band (preamble/ipg) being more beneficial. If b) and i) are objectives
then I am not sure there are many choices other than in-band.

Now, if EFM Service Providers want side-band (preamble/ipg or any other added SONET/SDH like) 
solution (and hence a requirement) then objectives can be accordingly, i.e. a) and ii) from above. 

But, if the method is not specified and left to open then I guess everybody is open to non-interoperability.

Sanjeev Mahalawat 

At 01:36 PM 09/15/2001 +0100, Bob Barrett wrote:
>I'm late in on this thread, so there may be a similar comment further up my
>in-box from somebody else.
>Geoff's observation is pretty fundamental:
>> My expectation is that the demarcation device will probably end
>> up with an IP address in order to support:
>>          SNMP for OA&M
>>          Firewall services for the subscriber
>> (That issue is, of course, beyond our scope)
>The logical conclusion of this observation is that EFM should make the OAM
>at layer two as simplistic as possible fulfilling only the basic
>requirements i.e. limited number of managed objects and limited echo (L2
>ping) test. Vendors can then leverage ietf standards (note: the users tends
>to like these) to implement ietf style 'standard' management functions.
>Isn't that what we all have in mind anyway :-).
>The open question then is will the service provider market accept in-band
>management i.e. management IP frames mixed with user traffic, or is there a
>real requirement for a side-band channel. If EFM does need to include a side
>band channel then all that it needs to be is a communications channel (bit
>stream), probably squeezed in the preamble or the IPG (we can debate that
>choice for a while). Vendors can then implement either a standards based
>method of comms over that channel or do there own thing. Personally I would
>expect vendors to choose something like IP over PPP for this.
>I can wrap this all up in a presentation for the next meeting if required.
>(Just seen Geoff's comment on this in response to Roy's thread; as a vendor
>we will probably want to support both in-band and side-band, standardised or
>not, but we would prefer a standard for side band as part of EFM).
>Bob Barrett
>> -----Original Message-----
>> From:
>> []On Behalf Of Geoff
>> Thompson
>> Sent: 04 September 2001 23:03
>> To: fkittred@xxxxxxx
>> Cc:
>> Subject: Re: [EFM] OAM loop back / echo server function
>> Fletcher-
>> I don't think this is a stupid question.
>> I don't think we need an IP level PING
>> A L2 ping would do, perhaps even better, the demarc would look for PING
>> type and then just swap SA & DA.
>> My expectation is that the demarcation device will need a MAC address
>> My expectation is that the demarcation device will probably end
>> up with an
>> IP address in order to support:
>>          SNMP for OA&M
>>          Firewall services for the subscriber
>> (That issue is, of course, beyond our scope)
>> Geoff
>> At 03:47 PM 9/4/01 -0400, Fletcher E Kittredge wrote:
>> >On Fri, 31 Aug 2001 14:11:54 -0700  "Geoff Thompson" wrote:
>> > > As I have said before, I do believe that we will need a
>> demarcation device
>> > > that has the capability to host OA&M functions.
>> > > We have talked about "loop back" from this point in the network.
>> > > Let us forevermore make that "PING"
>> >
>> >Geoff;
>> >
>> >         Apologies if this is a stupid question, but does PING in this
>> >context mean the utility that sends an IP ICMP ECHO REQUEST packet and
>> >listens for an ECHO REPLY packet?  If so, am I correct in thinking this
>> >means the demarcation device would require an IP address?
>> >
>> >thanks!
>> >fletcher