Specifications

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§ Distinguish between temporary traffic bursts that can be accommodated by
the network and excessive offered load likely to swamp network resources.
§ Work cooperatively with traffic sources to avoid TCP slow start oscillation
that can create periodic waves of network congestion.
§ Provide fair bandwidth reduction to reduce traffic sources in proportion to the
bandwidth being utilized. Thus, RED works with TCP to anticipate and
manage congestion during periods of heavy traffic to maximize throughput
via managed packet loss.
§ Are implemented in hardware in such a manner that entire packets need not
be stored in output line card memory queues for transmission. Only pointers
to packet cell data in memory are queued.
1.3 Addressing Scalability Concerns
The next generation of Internet backbone routers needs to deliver Internet scale,
Internet control, and unparalleled performance over an optical infrastructure.
Some of key attributes supported by the M-xxx that make it very scalable include:
§ Stable and complete routing software that has been written by Internet
experts and has successfully passed extensive interoperability testing in
large ISP networks.
§ Traffic engineering features that offer fundamentally new and sophisticated
control to support the efficient utilization of available resources in large ISP
networks
§ Packet processing capable of performing incoming decapsulation, route
lookup, queuing, and outgoing encapsulation at wire speed, regardless of
packet size or system configuration.
§ A switch fabric that has been oversized to provide an effective aggregate
bandwidth of 40 Gbps (8xOC-48) to support the transition to OC-48 based
cores.
§ A wide variety of interface types capable of delivering wire-rate performance
§ A chassis capable of providing a port density of at least one slot per rack-
inch
§ Mechanicals, serviceability, and management that make the system very
deployable in the core of a large ISP network
§ An ability to maintain overall network stability and adapt to a highly
fluctuating environment without impacting other parts of the network
A fully loaded system will forward packets at line rate and will have a route-lookup
performance of 40 million pps.
This is achieved by some of the following key design attributes:
§ Implementing an architecture that distinctly separates the functions
performed by the Routing Engine and the Packet Forwarding Engine---This
design segregates each component of the M40 system so that the stress
experienced by each part of the system does not negatively impact the
performance of the other part of the system.
§ Ensuring that the lookup performance of the Internet Processor ASIC is
never compromised---The Internet Processor ASIC is fully sized to perform
lookups at a rate of 40 Mpps regardless of how long the lookup or how large
the routing table. The 40 million lookups per second is achieved with 80,000
unique destination addresses as opposed to artificial benchmarks that do not
reflect the current state of the Internet.
§ Allowing the Packet Forwarding Engine to maintain forwarding performance
when there are high rates of updates to the forwarding table, by supporting
the revolutionary concept of atomic updates to its forwarding table.
1.4 The Juniper Networks Proposal
The M-xxx Internet backbone router is designed specifically for the specialized
needs of high-growth Internet backbone providers. It features market-leading
packet-forwarding performance, unparalleled port density and flexibility, and best-
in-class Internet software. The router delivers the bandwidth required by
providers to grow backbones to OC-48/STM-16 speeds, while also providing the
flexible MPLS traffic engineering tools to ensure greater control over traffic and to
increase bandwidth efficiency.