MS (Mobile Station)

The structure of the 32-bit MPLS header, as illustrated in Figure M-5, is as follows:

• Label: 20 bits matching the packet to the LSP.

• Experimental (EXP): 3 bits indicating the precedence, or packet queuing priority, for class of service (CoS) purposes.

• Stack (S): The stacking bit is set at 1 to indicate the last (i.e., innermost) MPLS header in a stack of headers. Outer tags carry a 0 bit in this position. MPLS virtual private networks (VPNs) involve hierarchical routing logic that requires multiple headers. As many as four MPLS headers can be contained within a stack.

• Time To Live (TTL): Copied from the IP TTL.The TTL is a hop count, with a default value of 64.

MPLS is based on several vendor-specific protocols, including Cisco’s Tag Switching, Ipsilon’s IP

Switching, and IBM’s ARIS technology. See also anycast, ATM, BGP, congestion, CoS, Data Link Layer, endpoint, FEC, flow, header, hop, IETF, IP, IPv4, IPv6, label, latency, LDP, LER, link, LSP, LSR, multicast, Network Layer, OSPF, packet, port, queue, RIP, router, routing, ToS, traffic engineering, TTL, switch, unicast, and VPN.

• A (Ampere)
• AAV (Alternative Access Vendor)
• abbreviation
• Abilene Project
• Abilene Project
• ABM (Asynchronous Balanced Mode)
• Above 890 Decision
• ABR (Available Bit Rate)
• absorption
• abstruse
• AC-3 (Adaptive Transform Coder 3)
• AC-3 (Adaptive Transform Coder 3)
• AC (Alternating Current)
• A Carrier
• acceptance angle
• Access BPL (Access Broadband over Power Line)
• Access BPL (Access Broadband over Power Line)
• access broadband over power line (Access BPL)
• access broadband over power line (Access BPL)
• access charges
• access circuit
• Access Manager
• access node
• access point (AP)
• access rate