on VoIP. OSS for Telecom Networks The CiscoWorks2000 QoS Policy Manager has a library of voice policies with pre- set QoS properties for routers and switches based on their role in the network, for example access versus core. VoIP SLAs are measured to provide information on latency, jitter and dropped packets, and to perform trend analysis. 13.6.2 Cisco and MPLS Increasing deployments of MPLS networks for traffic engineering benefits are help- ing service providers to manage their bandwidth better in order to ensure high per- formance levels for VoIP and other traffic. Traffic engineering enables traffic forwarding decisions to be made based on a greater number of variables than those considered by traditional routing protocols. Using MPLS features, service providers can guarantee bandwidth between end- points across an IP-VPN that uses MPLS. Note that these benefits are often tied to the use of other products of the solution provider. For example, such MPLS features provided by Cisco are geared towards networks which use the Cisco 12 000 Series Internet routers and Cisco 7500 Series routers, although they do not necessarily only work in such networks. Such MPLS technologies allow providers to guarantee ser- vices in a way that is analogous to Layer 2 Frame Relay and ATM. Cisco MPLS guaranteed bandwidth services' core features are: Traffic engineering which works at the control plane to allow multiple MPLS tun- nels with different priorities between pairs of sites. The use of classification, marking, policing, shaping, queuing and congestion avoidance to compensate for congestion in the engineered tunnel. MPLS fast rerouting establishes a backup network path with bandwidth and ser- vice quality requirements. If there is an interface or link failure, then traffic can be rerouted in milliseconds. The automatic bandwidth allocator dynamically varies the bandwidth of an MPLS traffic-engineered tunnel based on measured traffic load for extra-efficient bandwidth utilization. 13.6.3 Cisco and RSVP RSVP is an IP service 