Related
Documentation
MXSeries Ethernet Services Routers SolutionsPage•
•EthernetTerms and Acronymson page 3
•Networkingand Internetworking with Bridges and Routerson page 6
•Networkingat Layer 2: Benefits of Ethernet Frames on page9
•Networkingat Layer 2: Challenges of EthernetMAC Addresses on page 10
•Networkingat Layer 2: Forwarding VLAN TaggedFrames on page 11
•Networkingat Layer 2: Forwarding Dual-TaggedFrames on page 13
•Networkingat Layer 2: Logical InterfaceTypes on page 14
•AMetro Ethernet Network with MX Series Routers on page15
•Layer2 Networking Standards on page 17
Networkingat Layer 2: Benefits of Ethernet Frames
Inspite of the difficulties of using a bridge to perform the network roleof a router, many
vendors,customers, and service providers are attractedto the idea of using Ethernet in
asmany places of their networks aspossible.
Theperceived benefits of Ethernet are:
•Mostinformation starts and ends inside Ethernet frames. Today,this applies to data,
aswell as voice (for example,VoIP) and video (for example, Webcams).
•Ethernetframes have all the essentials for networking,such as globally unique source
anddestination addresses, error control, and so on.
•Ethernetframes can carry any kind of packet. Networking atLayer 2 is protocol
independent(independent of the Layer 3 protocol). Layer 2 networkswork for IP
packetsand all other Layer 3 protocols.
•Morelayers added to the Ethernet frame onlyslow the networking process down
(“nodalprocessing delay”).
•Adjunctnetworking features such asclass of service (CoS) or multicasting can be
addedto Ethernet as readily as IP networks.
Ifmore of the end-to-end transfer of information from a sourceto a destination can be
donein the form of Ethernet frames, more of the benefits of Ethernet can be realizedon
thenetwork. Networking at Layer 2 can be a powerfuladjunct to IP networking, but it is
notusually a substitute for IP networking.
9Copyright© 2010, Juniper Networks,Inc.
Chapter1: Overview of Ethernet Solutions