Networking

Cisco’s robust new offering

With enterprises looking to consolidate data centers and devices, Cisco's new ASR 1000 series router offers a compelling message: Do more with less.

In an exclusive Clear Choice test, the ASR not only moved traffic at 20Gbps but also did so while running QoS, security and monitoring functions on 120 million flows from hundreds of concurrent routing sessions.

The ASR also proved a capable performer when handling multicast and IPSec VPN traffic. And with a 40-core processor, the ASR has enough headroom to run firewalls, load balancers and other services without requiring additional hardware.

That's not to say the ASR isn't still a work in progress. Its data-plane capacity still needs to grow, and Cisco hasn't yet rolled out all the services that ASRs eventually will support. But this is a strong initial effort, well worth considering for the many enterprises looking to replace tiers of aging 7200 routers with a single more powerful system.

ASR 1000 series hardware — which began shipping last April and was upgraded in November (see announcement blogs) — has three components: an embedded service processor (ESP) for data-plane traffic, a route processor (RP) for control-plane functions and one or more line cards. The ASR family includes two-, four- and six-slot models; for this test Cisco supplied the top-of-the-line six-slot ASR 1006 with redundant RP and ESP modules and power supplies.

The ASR's most notable new feature is its ESP module, all of which features the 40-core Quantum Flow Processor (QFP).Through separate software licenses, QFP supports numerous services such as firewalls, NetFlow and Nbar classifiers and, in the future, caching load balancers. The ESP module also offers powerful QoS features, with 128,000 queues and support for up to 1,000 global policies and classification maps.

While the RP is functionally similar to Cisco 7200 routing modules, it scales higher; a million Border Gateway Protocol routes and hundreds of thousands of Open Shortest Path First (OSPF) routes are possible. Scalability also extends to the number of routing sessions: Our tests involved hundreds of concurrent OSPF sessions, something we haven't been able to set up with earlier midrange Cisco routers. The RP also offers an integrated session border controller for VoIP traffic and unified communications.

ASR line cards use the same shared port adapter (SPA) design as Cisco Catalyst 7600, Cisco 12000 and CRS-1 routers and are interchangeable among them, which should help control sparing costs. The SPA modules in turn fit into SPA interface processor (SIP) line cards.

The ASR's operating system is IOS XE, a Linux-based variant of Cisco's IOS software. XE looks and feels similar to IOS on 7200 routers, but it's actually just another process running under Linux. Unlike earlier versions where a problem with one process could crash the whole system, this modular design should help contain faults.

On the downside, the IOS XE command-line interface doesn't leverage powerful Unix/Linux shell features. Pattern matching of command output is limited; there's no inline configuration editing; and IOS XE does not accept IPv4 addresses entered using classless inter-domain routing (CIDR) notation.

We assessed the ASR with tests of unicast and multicast performance and scalability, high availability and IPSec tunnel capacity (see “How we did it”).

In unicast tests, we put an emphasis on services above and beyond simple packet blasting. In addition to enabling OSPF as the routing protocol, we configured the ASR 1006 so that each of 205 subinterfaces had two 103-line access control lists (ACL) applied. On the QoS front, the routers classified and queued up to four different traffic types. We also enabled unicast reverse path forwarding (uRPF) is correct and NetFlow accounting. (See the full system configurations used for testing.)

Many current routers and switches use NetFlow to track, at most, tens of thousands of flows. The previous high-water mark in any test we've done was 512,000 flows (see Cisco Nexus test).

The ASR's NetFlow cache can track 2 million flows at any one time. But with even more flows – and our tests introduced 120 million flows in as little as 12 seconds – the ASR will simply do “emergency aging” of older flows with no performance penalty. This is with full NetFlow monitoring; larger numbers of flows could be monitored using sampling techniques.

We also ran OSPF on a large scale, both in terms of session count and routing table size. Cisco configured OSPF to run on each of 205 subinterfaces – 20 on each of 10 1-gigabit interfaces and five on one 10-gigabit interface. In contrast, many enterprise routers run one or at most a handful of OSPF adjacencies.

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