Foundry NetIron M2404C and M2404F Metro Access Switches
Network Administration Tools (Rev. 03)
MEF OAM
© 2008 Foundry Networks, Inc.
Page 6 of 155
Two-way Connectivity, Jitter, Frame-Loss, Latency
In the default configuration, the device will not issue two-way service assurance tests. All two-way
tests must be configured as specific tests with the following parameters:
•
The OAM Domain to which this process belongs
•
MAC Address to test (or multicast)
•
Test Period (e.g., once every 60 seconds)
•
Size and Number of packets to send in each test.
When a device sends a connectivity test request, it stores a copy of this request in the response
bucket. This copy exists for timeout validation in case no response arrives.
Devices may send Connectivity Test Requests – they can be directed to a specific MAC address
(specific target MAC on specific VLAN) or multicast (to all OAM domain members on the
specific VLAN). For spreading the Connectivity Test Request multicast, the user should manually
execute OAM ping.
All the devices receiving a Connectivity Test Request on the specific VLAN must perform the
following:
•
If it is a multicast - forward it as a multicast.
•
If this PDU is not directed to the current device stop processing this PDU.
•
Otherwise, if this PDU is a Connectivity Test Request, send a unicast Connectivity Test
Response OAM PDU to the source device on the same VLAN this PDU was received.
•
Connectivity - Update the timestamp of this device on this specific VLAN
last seen on
network
field.
When a device receives a
Connectivity Test Response
, it should handle it as follows:
•
Add a record of this PDU to the connectivity cyclic queue of the received OAM PDUs for
the specific MAC address in the specific VLAN.
•
Calculate the jitter for the MAC Address for the specific VLAN (contained in this PDU)
based on its timestamp and the local receipt timestamps of previous connectivity test
responses (variance of difference between connectivity tests sent timestamp and
connectivity test local receipts timestamps).
•
Calculate the latency per bucket (mean of differences between connectivity tests sent
timestamp and connectivity test local receipts timestamps).
•
Calculate Frame-Loss per bucket (difference between connectivity tests sent and
connectivity test responses received, in percent).
•
Connectivity - Update the timestamp of this device.
The results of the SA Metrics may be presented through the CLI, or as log lines. In case of
insufficient network performance, SA Metrics may trigger log entries to be generated on a bridge
or transferred to a Syslog server.
MAC Traceroute
MAC traceroute implements a functionality that is similar to the Layer 3 traceroute functionality
but is performed at Layer 2 (at the MAC sub-layer). In the default configuration, the OAM MAC
traceroute service is disabled. To enable MAC traceroute, the user should use the corresponding
CLI command. MAC traceroute communicates using both unicast and multicast PDUs, obligating
the user to specify a destination MAC address. The source device transmits MEF OAM PDUs with