re 10Mbps Ethernet, Fast Ethernet (100Mbps), Gigabit Ethernet (1Gbps, referred to as GigE), and 10 Gigabit Ethernet (10Gbps, referred to as 10GigE). Currently, there is also work ongoing in the development of 100Gbps Ethernet. However, of the formal standards, 10GigE is quite new, and which of the standards will gain the widest commercial accep- tance remains to be seen. GigE and 10GigE are the two standards of interest to access network, MAN, and WAN providers. As discussed in the following sections, three standards from the IEEE aim to provide the core technology for the new data-centric public network of the peer-to- peer model (see Figure 11.14): 10GigE-10GigE, IEEE standard 802.3ae, supports 10Gbps and is tar- geted at the metro core and wide area networking. Along with operating at high speeds, 10GigE networks can unite LANs and WANs under a single technology. Ethernet First Mile (EFM)-EFM, specified under IEEE standard 802.3ah, supports 1Gbps and is targeted at the first (or last) mile. Resilient Packet Ring and other new standards-Resilient Packet Ring, specified by the IEEE 802.17 working group, is a standard for the optimized Chapter 11 Optical Networking Metro Core Metro Access Ethernet Switch Colocation Ethernet 10GigE Ethernet Ethernet Switch Regional Access Customer Facility Switch Switch Ethernet Approximately Switch 0.5 Miles Gigabit IP Network Router Figure 11.14 The Ethernet metro network transport of data traffic over fiber rings. Its purpose is to provide the same resilience that SDH/SONET networks offer (50-millisecond restoration), but by using packet-based transmission rather than circuit-switched connec- tions. The main goal is to increase the efficiency of IP services and Ethernet. 10GigE Today, 10GigE, which is in the early stages of deployment, is the highest-bandwidth Ethernet offering. Some of the main 10GigE applications include colocation of car- rier facilities, inter-POP connectivity, storage area network (SAN) connectivity, data center disaster recovery and mirroring systems, mul