ITEXPO begins in:   New Coverage :  Asterisk  |  Fax Software  |  SIP Phones  |  Small Cells

Feature Article
September 2002

Performance Management: Driving The Growth Of Private IP Services


As the market for frame relay services matures, service providers must grow revenues against increased levels of competition, leading to intense pressure on margins. At the same time the emergence of new services based on the ubiquity and low cost of the public Internet have added further pricing pressure. While robust site-to-site IP-VPN services across the public Internet are on the verge of becoming a viable choice for many large business customers, an increasing number of small to medium-sized businesses are adopting IP-VPNs. Meanwhile their Fortune 1000 counterparts evaluate the technology for large-scale deployment, in pursuit of potentially significant cost savings.

In response to the drive towards native IP connectivity services, over both public (Internet) or private (frame relay/ATM) transport media, major frame relay providers have introduced new Private IP services. These services are sometimes called �IP-aware frame relay services.� These services, typically based on MPLS and DiffServ technologies, offer a range of advanced IP service enhancements to the installed base of frame relay customers. This approach brings the benefits of low migration effort, inherent security, and reliability, further differentiating frame-based services against potentially less expensive, Internet-based alternatives.

The Main Drivers Behind This Growth Are:

  • Improved disaster recovery � Every enterprise is (or should be) concerned about disaster recovery plans. IP networks can more easily recover from �site down� situations. Rerouting IP addresses to a new location is easier than re-establishing a large number of frame relay PVCs.

  • Desire for native IP-based services � The increased use of Web and IP-based applications drives the need for IP-aware networks. With more applications transiting the enterprise WAN, network managers need more control over how WAN bandwidth is used. They need to ensure that lower priority applications, like e-mail and Web surfing, do not impact mission critical applications, such as CRM or database access. IP features such as class of service (CoS) allow the network manager to properly engineer his network bandwidth.

  • Reduced WAN complexity � The use of IP routing, rather than frame relay PVCs, simplifies the configuration effort for enterprise access routers, resulting in IT staffing cost savings.

  • Increased meshing of frame relay-based networks � IP applications such as VoIP, are driving an increasing need for branch sites to communicate directly to each other (mesh topology), rather than through a central site (hub and spoke topology). Private IP services eliminate the meshing costs incurred with traditional frame relay services.

  • Continued skepticism over use of the public Internet for mission-critical networking � Private IP enables a VPN to be established across the frame relay infrastructures. Frame relay is inherently more secure than the public Internet, while reliability is less likely to be compromised since traffic typically resides on a single frame relay network rather than transiting a variety of ISP networks.

Guaranteed Service Is Key
Guaranteed service quality is a key component to the success of Private IP Services. Before enterprises will place mission-critical traffic on IP services, they will need guarantees on the quality of service (QoS). They need reliability and predictability. Each enterprise has a wide variety of applications, all of which share the same WAN connection. For proper operation over the WAN, each application has specific expectations for the available bandwidth, packet loss, and delay. (Table 1 highlights some common applications and their sensitivities.)

Table 1

Bandwidth Sensitivity Packet Loss Delay Sensitivity
File Transfer High High Low


Low Medium High
E-mail Low High Low
Telnet Low High Medium
e-Commerce Medium High High

In general, if the WAN does not operate as expected, applications become unusable. What is the impact to voice quality if a large file transfer preempts voice traffic from using the WAN? At best, the quality of the call may seriously degrade. At worst, the call will be dropped. Private IP services will typically manage the quality of the connectivity by using the class of service (CoS) mechanisms built into IP. IP CoS enables the customer to allocate a defined portion of bandwidth to a specific type (class) of traffic. This is at once appealing � because of the added flexibility and bandwidth usage it brings � and necessary, since IP traffic connections do not have an assigned amount of bandwidth in the same way as frame relay PVCs have a Committed Information Rate (CIR). Therefore, the ability to differentiate traffic and guarantee performance is required to meet the enterprise requirements of reliability and predictability and is an integral part of a Private IP solution.

The Challenge: Performance Management
So we know that IP has the CoS mechanisms to provide an acceptable quality of service. However, in order for service providers to provide SLAs that address IP QoS, they must be able to monitor, measure, and guarantee the IP connection behavior, from end to end (see Table 2).

Table 2

Challenge Solution
  • How much traffic is being used for each class of service?

  • Need the ability to measure total throughput, both ingress and egress, for each class of service.
  • Has the correct percentage of bandwidth been assigned and delivered for a given traffic class?
  • Need the ability to measure throughput, above/below CoS policing thresholds, for each class of service.
  • Is site-to-site IP connectivity available?
  • Need the ability to verify IP connectivity between subnets.
  • Is the site-to site IP connection meeting the defined performance criteria or SLA?
  • Need the ability to measure latency, availability, and packet delivery ratio.
  • Do the SLAs and performance information reflect real-world network performance as seen by the customer?
  • Need the ability to collect and measure all performance data at the customer location.
  • Needs SLAs that are based on a clear "IP demarc" at the customer location.

At the same time, the service provider is under constant pressure to reduce their operating expenses. How can service providers guarantee performance while reducing operational support costs? (See Table 3.)

Table 3

Challenge Solution
  • Reduce MTTR (mean time to repair) by reducing problem isolation time.
  • Operations staff requires real time access to remote site performance data at the central operations center.
  • Reduce cost of Operational support.
  • Eliminate the need to technician dispatches to resolve service problems.
  • Verify that IP service has been provisioned correctly between service demarcation points.
  • Toolset to remotely verify IP connectivity between subnets.
  • Avoid the delays inherent in finger pointing between service providers and enterprises.
  • Enterprise and service provider must be using the same data to troubleshoot problems.

Private IP services have many benefits that enterprises are looking for. However, before enterprises migrate to Private IP, they need guaranteed performance, which is achieved through CoS. In order to manage CoS and guarantee performance, usage and performance data needs to be collected from every site in the network and needs to be available to both the enterprise and service provider for CoS service level validation. Additionally, in order to guarantee performance in a timely and cost efficient manner, usage and performance data needs to be available to both the enterprise and service provider for collaborative operational troubleshooting and the data needs to be available in real time.
If performance management is included in the Private IP service, it will drive growth in the emerging Private IP services market.

  • Enterprises will obtain the reliability and predictability of frame relay along with the flexibility of IP.
  • Service providers will be able to develop differentiated and/or value-added services.
  • Service providers will be able to provide an IP demarcation point that clearly delineates the point of service delivery at the customer location.
  • Service providers and enterprises can validate SLAs from a customer-centric viewpoint.
  • Service providers and customers will have collaborative performance views, thus reducing operational costs, increasing customer satisfaction, and improving customer relationships.

Private IP services will only be successful if both the enterprise�s and service provider�s requirements for performance guarantees and service manageability are met. Private IP services must be designed and offered such that performance is managed and guaranteed in a cost-effective manner in order to make the service easy to sell and easy to run. Thus, one of the key ingredients for the success of Private IP is performance management, which must be viewed as a mandatory element of any Private IP service offering. c

Mr. Bob Norberg is director of Private Transport Services at Visual Networks and Mr. Peter Luff is director of Service Creation at Visual Networks. Their focus is on developing WAN performance management solutions that help increase network reliability and revenues and creating NSP services around products that dramatically reduce operational expenses and the total cost of ownership for enterprise and service provider customers. For more information visit the company�s Web site at www.visualnetworks.com.

[ Return To The September 2002 Table Of Contents ]

Today @ TMC
Upcoming Events
ITEXPO West 2012
October 2- 5, 2012
The Austin Convention Center
Austin, Texas
The World's Premier Managed Services and Cloud Computing Event
Click for Dates and Locations
Mobility Tech Conference & Expo
October 3- 5, 2012
The Austin Convention Center
Austin, Texas
Cloud Communications Summit
October 3- 5, 2012
The Austin Convention Center
Austin, Texas