Juniper JUNOS OS 10.4 Manual page 25

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MSTP—Multiple Spanning Tree Protocol. A spanning-tree protocol used to prevent
loops in bridge configurations. Unlike other types of STPs, MSTP can block ports
selectively by VLAN. See also RSTP.
OAM—Operation, Administration, and Maintenance. A set of tools used to provide
management for links, device, and networks. See also LFM.
PBB—Provider backbone bridge.
Q-in-Q—See 802.1ad.
PBBN—Provider backbone bridged network.
RSTP—Rapid Spanning Tree Protocol. A spanning-tree protocol used to prevent loops
in bridge configurations. RSTP is not aware of VLANs and blocks ports at the physical
level. See also MSTP.
S-TAG—A field defined in the IEEE 802.1ad Q-in-Q encapsulation header that carries
the S-VLAN identifier information. See also B-TAG.
S-tagged service interface—The interface between a customer edge (CE) device and
the I-BEB or IB-BEB network components. Frames passed through this interface contain
an S-TAG field. See also B-tagged service interface.
S-VLAN—The specific service instance VLAN identifier carried inside the S-TAG field.
See also B-VID.
switch—A network device that attempts to perform as much of the forwarding task in
hardware as possible. The switch can function as a bridge (LAN switch), router, or
some other specialized device, and forwards frames, packets, or other data units. See
also bridge.
virtual switch—A routing instance that can contain one or more bridge domains.
VLAN—Virtual LAN. Defines a broadcast domain, a set of logical ports that share the
same flooding or broadcast characteristics. VLANs span one or more ports on multiple
devices. By default, each VLAN maintains its own Layer 2 forwarding database
containing MAC addresses learned from packets received on ports belonging to the
VLAN. See also bridge domain.
Y.1731—The international standard for Ethernet Frame Delay Measurements (ETH-DM).
At this point, these acronyms and terms are just a bewildering array of letters and words.
It is the goal of this manual to make the contents of this list familiar and allow you to
place each of them in context and understand how they relate to each other. To do that,
a basic understanding of modern Ethernet standards and technology is necessary.
Ethernet Networking
Networking and Internetworking with Bridges and Routers on page 6
Network Addressing at Layer 2 and Layer 3 on page 7
Networking at Layer 2: Benefits of Ethernet Frames on page 9
Networking at Layer 2: Challenges of Ethernet MAC Addresses on page 10
Networking at Layer 2: Forwarding VLAN Tagged Frames on page 11
Chapter 1: Overview of Ethernet Solutions
5