Optical Ethernet
Based fundamentally on Ethernet, Optical Ethernet MANs let carriers deliver standard, well-known 10/100M bit/sec or 1G bit/sec Ethernet interfaces - the same as those used to easily connect office networks today.
And instead of a SONET ring, the metropolitan backbone for Optical Ethernet networks will be based on the 10G bit/sec Ethernet standard from the IEEE working group 802.3ae.
Optical technologies enable Ethernet networks to extend over much greater distances than campus Ethernet nets. Running over single-mode fiber, Optical Ethernet lets links in the network range from 3 to more than 6 miles in the case of 1310-nm wavelength technology, and up to 43.4 miles for 1550-nm wavelength technology.
Key components of Optical Ethernet are the abilities to segregate traffic of different users and to deliver the particular service level each user purchases.
Traffic segregation is accomplished by using the IEEE 802.1pQ virtual LAN (VLAN) standard. This standard lets Optical Ethernet networks mark each user's traffic with a VLAN tag as it enters the network and then use this tag to keep each user's traffic separate as it crosses the network. Of course, 802.1pQ was designed for enterprise networks and the number of possible VLAN tags is too low. Work is under way in IEEE to extend this number from 4,096 to approximately 16 million.
Optical Ethernet can also deliver guaranteed levels of latency, jitter and bandwidth.
From Optical Ethernet for metropolitan nets, Network World Tech Update, 04/02/01.
Additional resources
Corporate Networks Topic: Optical
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