MPLS faces management challenges

A networking protocol that is just coming into its own promises improved quality of service through better bandwidth utilization, but system administrators are not off the hook when it comes to the management of this new infrastructure.

Known as Multi Protocol Label Switching (MPLS), the technology is a routing protocol that uses labels or tags that hold forwarding information and are attached to IP packets. MPLS ensures that all packets in a certain flow use the same route over the backbone, and is expected to deliver the quality of service (QoS) required to support real-time voice and video as well as service level agreements (SLAs) that guarantee bandwidth.

However, there are management challenges that arise with MPLS and several companies have released products aiming to tackle them. Last month, RiverSoft Corp. of London released new versions of its network management operating system (NMOS) and its Fault Manager product offering, which now support MPLS. According to the company, managing these networks is challenging because existing management tools don’t provide a clear picture of what’s happening.

“MPLS has many features and benefits for service providers and large enterprises…such as its traffic engineering, guaranteed bandwidth, QoS and fast re-routing capabilities,” said Paul Johns, vice-president of worldwide marketing for RiverSoft. “There is one problem, however. What if MPLS breaks? Who is watching it.…MPLS networks are invisible to existing traditional network management systems.”

Johns explained that the RiverSoft NMOS builds a topology of the MPLS network, then the Fault Manager steps in to ensure it is operating correctly. “[Fault Manager] will process MPLS alerts and perform correlation against those alerts to help operators quickly pinpoint troubles.”

Within the NMOS the company has developed two MPLS Discovery Agents – one which uses simple network management protocol (SNMP) and the other which uses Telnet – that uncover the existence and connectivity of MPLS networks and retrieve connectivity and protocol-specific information from the network. Once discovered, the RiverSoft NMOS GUI delivers visualization of the label switch paths that have been created throughout the network and network managers are alerted to problems with connectivity assurance and service views.

RiverSoft’s Fault Manager offers event management, event prioritization, impact analysis and root cause analysis to ensure MPLS networks maintain constant high availability.

According to Cisco Systems Canada’s James Moffat, consulting systems engineer, there are some off-the-shelf network management products that can manage certain aspects of MPLS nets. He said that, for example, if a user is looking at a router and trying to determine its interface utilization, many SNMP products can do the trick.

“However, if you wanted to get more in-depth, like looking at what types of MPLS frames are being sent, then products become MPLS-specific,” Moffat said.

He added that Cisco is working with management partners including the likes of Concord Communications, which provides QoS assurance software for Cisco MPLS architecture; Wandl Inc., who’s MPLSView solutions offer traffic management and traffic engineering; and Syndesis, which provides provisioning and monitoring offerings.

The more choice the better for one Canadian telecommunications provider. GT Group Telecom is currently in the process of implementing its MPLS backbone. According to Michael Stephens, vice-president of product marketing for GT in Toronto, MPLS looks inviting ,especially when compared to Frame Relay or ATM.

“You have a provisioning nightmare (with Frame and ATM) of having to provision individual PVCs (permanent virtual circuits), and you have to have all of the monitoring tools to ensure you have adequate bandwidth on those PVCs,” Stephens said. “Then you have to make sure you’ve set up your routing properly and that you have optimized the routing flows based on the fact that everything is coming back through one central host.”

MPLS, on the other hand, being a Layer 3 service, means it is a routed service. “You don’t have to provision PVCs. You literally just have to plug the person into the network and give them a user ID and they are off. It is connectionless.”

Stephens said GT is working with Cisco to implement its MPLS architecture, which is expected to be rolled out within the next three to four months. Although Stevens could not comment on which tools GT plans to use to manage the network, Cisco’s Moffat said that Service Assurance Agents, which act as application probes to sample how the network is behaving, are already embedded in the Cisco IOS.