TABLE OF CONTENTS Complementary to IP QOS technologies, there are a set of additional techniques and technologies that have been developed within the IP technical community and which further enable IP networks to be engineered to support tightly bounded SLA commitments. While these technologies are not covered in detail in this book, they are described here in overview.
Fast IGP convergence. Advancements and developments in the implementation and deployment of IGPs have resulted in significant improvements to the IGP convergence times that can be achieved without any compromise in routing protocol stability. This has resulted in convergence times of a few hundred milliseconds being realistically achievable in well-designed IP networks today [FRANCOIS], which significantly reduces the loss of connectivity experienced following network element (e.g. link or node) failures. This reduction in convergence times allows higher availability targets and lower packet loss rates to be offered for SLAs across all service classes. Consequently, fast IGP convergence is also recommended as a foundation for multiservice IP network designs.
Fast reroute technologies. Developments in local protection schemes for both IP and MPLS - generically termed fast reroute (FRR) technologies - enable further reductions in the loss of con nectivity following network element failures.
MPLS traffic engineering fast reroute. The use of MPLS traffic engineering (TE) for admission control is discussed in Chapter 4, and for bandwidth management is discussed in Chapter 6. However, there is another application of MPLS TE which is in the context if MPLS TE Fast Re-route...
