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Re: [EFM] OAM loop back / echo server function


At 06:05 PM 9/4/01 -0500, Roy Bynum wrote:

Would a MAC Control frame with a specific opcode  be usable as an L2 ping.  This would take the frame all the way to the MAC control layer, through all of the PHY and RS.

This function "could" be added to MAC control.
It is not clear that there would be any special reason to do so.
You would have to make a convincing case that there was some special advantage to doing this vs. using an existing, well known protocol. According to my file copy of RFC 1060 (very old version of Assigned Numbers) decimal 36864 (9000 Hex) packet type is assigned to Loopback.

It is not clear to me that restricting the path of a Loopback/Echo/Ping to just the [MAC Control][MAC][RS][PHY][Medium][PHY][RS][MAC][MAC Control] would be any advantage. After all, the person machine that wants to do the test would have to open a communications path to the testing [MAC Control/OA&M] anyway.

There could also be a command within the OAM functionality that would generate a special MAC Control frame that would have an opcode that would specify a test pattern in the "parameters" field of the frame.  This could potentially provide a very valuable remote trouble shooting tool for service providers.

Roy Bynum


At 03:02 PM 9/4/01 -0700, Geoff Thompson wrote:


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)


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"


        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?