Tuesday, March 9, 2010

Service Assurance: IP Quality of Service

This week I will be attending the EFIPSANS technical review in Brussels. One aspect of this project is mechanisms for delivering QoS for IP networks which coincidentally was the subject matter of my very first research project called EUROBRIDGE, a EU funded RACEII project, back in 1993 when I worked for Broadcom Eireann Research! I remember clearly a conversation I had with a colleague of mine while walking down the street in Aveiro, Portugal coming from a project meeting in November of that year. We were talking about how the Internet needed a killer application and we were at pains trying to think of what that could be. I had yet to see a web browser, which followed soon after and how things have change since! At that time IP networks were used for data networks and data services only and circuit switched networks was what was required for serious business.

Despite IP having since becoming ubiqitious, somethings have never changed. IP is fundamentally a "best-effort" technology which makes assuring IP services difficult and while DiffServ and IntServ provided technical ways of achieving this, the business case for doing so was weak. ISPs generally competed for customers based on two variables: price and bandwidth. In recent years, through convergence and new market entrants, competitive pressures have seen a decline in revenues from bandwidth which was sold effectively as "dumb pipes" and operators now seek to restore revenue growth through the provisioning of premium services such as triple play (Phone, TV and Internet). Therefore the need for assuring services delivered on IP networks is of renewed importance. The business environment has changed.

Research projects, like EFIPSANS, is defining an autonomic architecture for the self-management of IPv6 networks. One of the most important functions of such a system is the ability to continuously 'sense' how its performing within its environment. Telecoms networks do this by continuously collecting and analysing performance statisitics - millions of them 24/7, 365 days a year. From an end-user or customer perspective however, their main concern is of course that the services they use and pay for are performing end-to-end to the level that is expected. Our research in EFIPSANS is taking a customer-centric or path-based view for performance monitoring rather than a network-centric view.

The first challenge is to gather the most relevant performance data that will tell us something about the performance along the path. One thing that's clear is that there is no one tool that fits all. The following is a list of some key tools or techniques that can be used:
  • traceroute - discovers IP addresses along a path including the round-trip delay
  • hello - can be used to detect link failures along a path
  • pathchar - used to estimate link bandwidth and estimated available bandwidth
  • IPMP - used for measuring one-way delay
  • IPFIX - used to export IP flow information from an single observation point
  • Probes - used to mimic the experience of user data
  • SNMP - provides a more device-centric view on performance
The above may help an operator to identify or confirm that there is a problem with a specific path in the network, although it might be difficult to identify where on the path or why there is a problem. In EFIPSANS we are working on an IETF Internet Draft proposal for helping do just that by defining a new protocol that can be used to retrieve management information from each node along a path that will facilitate more targetted monitoring and diagnosis for fault recovery, fault mitigation as well as optimisation.

While its one thing to gather performance data using some or all of the above, its what you do with it that really counts. This is where vendors of service assurance solutions can differentiate themselves by offering functionality that offers capabilities that can add real value to their customers. Where these solutions can really make a difference is by identifing potential problems before they result in an outage or service degradation so that preventative measures can be taken resulting smooth operation of revenue generating services.

Sunday, March 7, 2010

Haiti's woes continue

I was listening to the BBC's Digital Planet podcast this week and an argument between local ISPs and NGOs in following the Haiti earthquake caught my attention. Following the earthquake, the NGOs came in and setup their own communications networks to assist in the relief effort under the assumption that the existing infrastructure was destroyed. However, it turns out that this wasn't necessarily the case and there has been some cases reported where survivors trapped under rumble were able to use their mobile phones to send messages to the outside world. By setting up ad-hoc networks, the NGOs inadvertently have been causing disruption to the existing networks that either remained operational or have since been restored which is the cause of the current dispute.

This incident outlines the need for network planning with current radio technology. As I've mentioned before the air interface is a hostile environment and unless deployed infrastructure is done in a co-ordinated manner then operational problems are inevitable. Its only to be expected that the Haiti ISPs would get upset about problems incurred due to the NGOs networks because network outages equates to zero revenues.

Of course if the networks deployed in Haiti were capable of self-organising then they would be able to adapt to the changed operational environment by re-configuring themselves so that they could continue to perform optimally as the networks are being restored. Even if the ad-hoc network technology was able to self-organise, this would still be problematic for the networks deployed by the established network operators as these networks would have been planned in the traditional way.

This episode is a timely reminder that even if LTE promises full SON capability, deployment of LTE will still require some replanning of 2G and 3G networks to support at least inter-RAT handover for as long as operators require these network technologies to co-exist. Expect this to be the case for quite some time yet as operators seek to maximise their return of investment in their 2G/3G networks.

Webinars

Last week I attended a webiner called Generating New Revenue Streams While Improving Differentiation and Efficiency by Nokia Siemems Networks. Subscriber experience will be the number one business goal for service providers in 2012 according to a study carried out by NSN. This described the various solutions NSN have to achieve just that.