Ethernet OAM BCPs Please are there any yet???

Are there any best common practices for the CFM levels use
Since my pure Ethernet aggregation layers are small I believe I only need
two CFM levels
I plan on using Level 5 between CPEs managed by us and Level 4 between
Aggregation devices -that's where MPLS PWs kicks in
So leaving Level 7 and Level 6 for customers and carrier-customers
respectfully -would this be enough please?

I'm also interested on what's the rule of thumb for CCMs Frequency, Number
of Packets, Interpacket Interval, Packet Size and Lifetime for the
particular operation
Thanks a lot for any inputs


The ITU recommend the following levels:

5,6,7 = Customer
3,4 = Provider
1,2 = Operator
0 = Local segment

I don't know if there are any rules of thumb for the CCM interval - faster is more sensitive & unstable, slow is sluggish but stable. The spec allows between 3.33 ms and 10 minutes in 7 steps, with 1s being the midpoint. So we use 1s intervals.

I'm not sure if the other parameters you mention are configurable for CCM. I think the packet has a constant size. Are you wanting to also do Y.1731 performance management?


Thank you so much Jonathon.
This is exactly what I what I was searching for.
Oh and yes I should have mentioned I'd like to do the Y.1731 and measure the
delay and delay variance

Just yesterday evening I found a great article about how ATT did theirs
active measurements though for IP - wondering if I could do the same for my
They used dedicated servers and I'll be running this form the routers
ME3600X and CX and ASR9K so I'm a bit worried about the scaling of the whole

ATT basically used two probes and each 24-hour day is divided into 96 test
cycles of 15 minutes

A Poisson probe sequence of duration equal to the test cycle
- Poisson distribution with average interarrival time of 3.3 s
- Packet size of 278 bytes, including headers
- UDP protocol

Two periodic probe sequences in every test
- Interval of 20 ms between successive packets (or 50 packets/s)
- 1 min duration
- Random start time within the 15 min cycle
- Packet size of 60 bytes (including headers)
- UDP protocol


I don't know if any Y.1731 gear will do anything other than constant interval probes. I'm also not sure what the values of randomly spaced probes would be.
As far as I know the Y.1731 performance measurement probes are intended to be used to obtain performance data on circuits with as little impact on the available bandwidth as possible. Using a random departure time sounds like the sort of load test where you want to generate a synthetic data stream and consume bandwidth.


I have used BRIX active measurement for IP for many years, but here is a
link that describes BRIX in conjunction with ADVA for Ethernet probes.

There is an article in IEEE Communications Magazine circa 2004-2005 by AT&T
researchers describing their roll your own active measurement system,
theoretical assumptions, and theory of probe data collection.