IP Over Direct Links: IP Over Sonet

The explosive growth in Internet traffic has created the need to transport IP on high-speed links. In the days of low traffic volume between IP routers, bandwidth partitions over a common interface made it attractive to carry IP over a frame relay and/or an ATM backbone. As the traffic grows, it is becoming more desirable to carry IP traffic directly over the synchronous optical network (SONET), at least in the core backbone with very high pairwise demand. Currently, the focus of IP transport continues to be data-oriented. However, a significant trend in the industry, with the emergent demand for the support of real-time IP services (e.g., IP telephony), is the development of routers with sophisticated quality of service (QoS) mechanisms. We see details of IP Transport over SONET and give an overview of the protocol and performance considerations that need to be taken into account. Then scalability and performance considerations for transport protocols and outline for functions of protocols that can be used to transport IP on very-high-speed links are discussed. Finally, the solutions to improve Quality of Service (QoS) for VoIP services are discussed.