• United States
by Steve Taylor and Joanie Wexler

QoS gets easier

Jun 12, 20033 mins

* Device- vs. net management-based QoS

We’ve been discussing the fact that vendors such as Alcatel, Cisco and Nortel are simplifying the task of setting quality-of-service parameters in network equipment to ease operations in running a converged enterprise network. A primary difference among vendors at this juncture is that Cisco is currently limited to QoS templates for voice over IP, while Nortel and Alcatel offer them for VoIP, video and data

Note that while we are discussing the comparative traits of these systems, the QoS-automation features don’t compete as stand-alone systems. You wouldn’t go shopping for a QoS provisioning system. More likely, you’d go in search of LAN infrastructure equipment, with the associated network management and QoS provisioning capabilities playing a role in your selection.

This time, we’ll take a look at what Cisco and Nortel do.

Unlike Alcatel (described last time), Cisco and Nortel come at QoS automation from a couple of directions: the device level or the network management level.

For example, says Ron Lifton, CiscoWorks QoS Policy Manager (QPM) product manager, “You can enable autoprovisioning using [the Cisco IOS operating system] on a device, and you can also do it through QPM network manager tools, which take a multidevice view.”

Nortel offers the same basic approach. “You can autoconfigure a switch at a time or push out policies from the Optivity Policy Server,” a module of Nortel’s Optivity Network Management System, explains Ralph Santitoro, Nortel director of network architecture.

In Cisco’s case, the device, IOS-based approach has a separate feature name, which is AutoQoS.  “With AutoQoS, network administrators can very precisely provision each interface with multiple parameters,” says product manager Tim McSweeney. “Those settings can then be propagated to QPM and pushed out to other devices across the network.” 

AutoQoS, currently in its first release, targets smaller organizations that want to run VoIP, have a data network enabled and have limited or no QoS experience.

The QPM-centric approach targets larger enterprises. There is a wizard for leveraging templates for voice, or administrators can customize templates for voice, video, and data traffic. An audit trail reveals changes that have been made to policies.

Nortel, which notes it has offered simplified QoS since 1999, breaks down traffic into four categories, which are subdivided into eight Nortel Network Service Classes.

For example, network control traffic is a traffic category that might be mapped to a “critical” Nortel service class. VoIP and video fall into the “Interactive” traffic category; VoIP and gets mapped to Nortel’s Premium service class and video gets mapped into the “Platinum” class.