Ethernet Oam Link-Fault Management References; Oam Messages; Figure 30: Oam Pdu Format - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - LINK LAYER CONFIGURATION GUIDE 2010-10-13 Configuration Manual

JunosE 11.3.x Link Layer Configuration Guide
Related
Documentation

Ethernet OAM Link-Fault Management References

OAM Messages

Destination Address =
01-80-c2-00-00-02
Slow protocol subtype = 0x03
226
For more information about interface types and specifiers on E Series models, see Interface
Types and Specifiers in JunosE Command Reference Guide.
Interface Types and Specifiers
For more information about 802.3ah link-fault management implementations, consult
the following resources:
IEEE 802.3ah-2004 (Clause 57, Operations, Administration, and Maintenance
[OAM])—Media Access Control Parameters, Physical Layers, and Management
Parameters for Subscriber Access Networks
IEEE 802.3ah-2000—Part 3: Carrier Sense multiple access with collision detection
(CSMA/CD) access methods and physical layer specifications
Because 802.3ah is an optional component and not all functionalities of OAM might be
supported on a particular system, discovery mechanisms are used to ascertain the
presence and capabilities of the remote peer.
Transmitted Ethernet OAM messages or OAM PDUs are of standard length, untagged
Ethernet frames within the normal frame length limits in the range 64–1518 bytes. The
maximum OAM PDU frame size exchanged between two peers is determined during the
discovery phase. OAM PDUs contain the destination MAC address of the slow protocols
multicast (0180.c200.0002) and an Ethertype of 8809. In a slow protocol environment,
the bandwidth required is minimal and the frame transmission rate is limited to a
maximum of 10 frames per second. The first octet of the frame payload is the slow
protocol subtype field and is set to 0x03. OAM PDUs do not travel beyond a single hop
and are transmitted at a rate limited to a maximum of 10 OAM messages per second.
Certain OAM PDU types might be transmitted multiple times to improve the probability
of their successful receipt on degrading, lossy links. Figure 30 on page 226 shows the OAM
PDU format.

Figure 30: OAM PDU Format

Source Address
Flags Code
The Flags field is used to inform the local state to the peer. This state is used in discovery
and in remote failure detection. The Code field denotes the type of OAM packet. The
format of the OAM Data/Pad field consists of TLV elements.
Four types of OAM messages are supported:
Ethertype = 8809 Payload
OAM Data / Pad
Copyright © 2010, Juniper Networks, Inc.
Frame Check Sequence