NSR® Non-Stop Routing for Breakthrough Reliability
The End of Router Downtime
In order to capture high-margin IP service revenues, network reliability is paramount. Carriers are dependent on mission critical and Real-Time services for revenue growth. Customers of these applications are unwilling to tolerate the best-effort service quality and periodic outages that characterize most IP networks today. The impact of router failure on a carrier's business can be devastating. Losing traffic and disrupting mission critical services has significant business impact including SLA penalties, customer service/maintenance issues, and customer churn.
Avici's NSR® non-stop routing technology delivers breakthrough reliability to IP networks, enabling carriers to achieve Five Nines availability in a single router,guaranteed. NSR® achieves this reliability breakthrough by providing true hot-standby protection of the route controller. Supported on all Avici Routers, NSR® not only protects Avici routers against control plane failure, it also enables in-service upgrades and protected configuration changes.
It is clear that the reliability of IP networks needs to be improved and in evaluating the methods available to improve router reliability, it is clear which method brings the most benefits:
Avici's NSR® Non-Stop Routing (Shipping and Certified by Customers)
Uses backup route controller to maintain all pertinent state information
and maintain adjacencies with surrounding routers
+ Telecom paradigm (Voice, ATM, etc.)
+ Preserves connectivity to peers and dynamic routing
+ No interoperability with other vendors required
+ In-service software upgrades
- More difficult for vendors to implement, but easier for operators
Protocol Extensions/Non-stop Forwarding/Graceful Restart (Not Available)
BGP, OSPF, IS-IS, LDP, and MPLS extensions needed to notify peer routers
to continue forwarding and receiving packets even if route processor
has failed
- Uses "stale" routing information during failure; routing loops and
black holes are possible
- Extensive interoperability required for each protocol
- No hitless software upgrades
- Competing drafts exist in IETF from legacy routing vendors
+ Easier for vendors to implement, but more difficult for operators
