way. At the present time, a good source of information is the tutorial prepared by the HSSG (IEEE 802.3, 2007a). Conclusion In this chapter we have examined a number of aspects related to the development of Eth- ernet in the wide area network environment. The rate of development of the technology, and indeed technologies that have a strong commercial relationship with Ethernet such as MPLS, OTN, and SDH/SONET, will provide both customers and providers with rich net- working capabilities and a plethora of choice. The manner in which Ethernet will be utilized will depend on many factors, including a network provider's current infrastructure, the provider's view of its future network architecture, and the migration path toward it. The rate of technology change means that it is difficult to predict the future of the technology and its relationship to other technologies. Nevertheless, there can be no doubt that Ethernet, in whatever guise, will play a significant role in future networks. References Allan, D., et al. (2006) Ethernet as Carrier Transport Infrastructure, IEEE Commun. Mag. 2:134-140. Clark, K., and Hamilton, K. (1999) Cisco LAN Switching, Cisco Press. Hussain, I. (2006) Ethernet Services over MPLS Networks, in Kazi, K. (ed.), Optical Networking Standards: A Comprehensive Guide for Professionals, Springer, 425-456. References IEEE (in progress) 802.1ah, IEEE Draft Standard for Local and Metropolitan Area Networks, Virtual Bridged Local Area Networks, Amendment 6: Provider Backbone Bridges. IEEE (in progress) 802.1Qay, IEEE Draft Standard for Local and Metropolitan Area Networks, Virtual Bridged Local Area Networks, Amendment 6: Provider Backbone Bridge Traffic Engineering. IEEE (in progress) 802.1ad, IEEE Standard for Local and Metropolitan Area Networks, Virtual Bridged Local Area Networks, Amendment 4: Provider Bridges. IEEE (2007a) 802.3, High Speed Study Group (HSSG). IEEE (2007b) 802.1ag, IEEE Standard for Local and Metropolitan Area Networks, Virtual Bridged Local Area Networks, Amendment 5: Connecti