Hosted Communications

Hosted VoIP services are proving an attractive option for many small to medium sized businesses, providing a low entry cost, hassle-free service. This places responsibility on the service provider to ensure that performance is acceptable and that problems are resolved promptly – however competition within the industry means that pricing, and hence operating costs, must be kept low. This is leading to increased awareness of the need for tools and technology that monitor the quality of services delivered to the customer and support remote problem resolution.

 

Hosted VoIP service providers delivering service to small business locations (10-100 employees) often find that the cost of placing dedicated test equipment on the customer premises is prohibitive. There are however highly cost-effective solutions available from a number of suppliers; these fall into two major categories:

 

(i)                  Passive (live call) monitoring

Embedded software agents in IP phones (e.g., Nortel or Polycom (News - Alert)), VoIP gateways or routers (e.g. Adtran) on the customer premises are able to monitor the quality of every call and report back to the service provider using RTCP XR (RFC3611) or SIP RTCP Summary Reports. This allows the service provider to track service levels, automatically detect poor quality calls and perform problem identification.

 

(ii)                Active (test call) monitoring

Active test agents can be installed on servers (e.g. an existing file or print server), integrated into customer premises equipment, or downloaded on demand to support troubleshooting. This type of agent supports pre-deployment testing, SLA monitoring and on-demand troubleshooting. Telchemy’s (News - Alert) DVQattest agents, for example, can both generate VoIP test calls and perform in-depth IP problem diagnosis and location, and are available in both permanently installed and downloadable forms.

 

Active and passive solutions are entirely complementary. Passive monitoring provides information on what actually happened on customer calls and generates no additional traffic in order to measure quality levels. Active testing provides the ability to detect some problems before they affect users, and supports more advanced troubleshooting. 

 

 

A customer location has 20 IP phones, and both the IP phones and the router have been supplied by the service provider and are equipped with passive monitoring agents (e.g. VQmon). There are two problems affecting service quality – congestion on the T1 connection to the customer and a duplex mismatch problem on the customer premises that affects 8 of the 20 IP phones.

 

Each call that is made to or from an IP phone on the customer premises is monitored by the IP phone and also by the agent software in the router. For each call, an end of call report is automatically generated and sent back to (e.g. an SQmediator located at) the service provider. The call report contains metrics for both the send and receive directions, and includes MOS scores, packet loss, jitter and analog signal metrics. 

 

The service provider observes that the customer is experiencing quality problems, and looks at the call quality records from the past 24 hours. They observe the following:

 

(a)    There are a significant number of bursts of lost/ discarded packets that appear to intermittently affect calls from all the IP phones. Bursty packet loss and discard are a strong indication of a congestion problem, and because this affects all the users, it suggests a problem on the access link (T1).

 

(b)   There appears to be packet loss affecting only some of the IP phones, and the IP phones report packet loss even at times when the router reports no loss. This strongly suggests a layer 1/2 problem (such as duplex mismatch) on a common LAN segment that connects to the affected IP phones.

 

From an analysis of the data provided by the embedded agents, the service provider was able to quickly understand that the customer was experiencing quality problems, and was able to diagnose the problems from call quality records. 

 

If the service provider were also utilizing an active test system with downloadable agents, they would be able to identify more specifically that the customer LAN problem was in fact a duplex mismatch problem, and isolate the specific link(s) on which congestion was occurring. 

 

 

The essential tools that service providers need to monitor hosted services are readily available, and provide the ability to continuously track service quality and diagnose problems. The use of integrated agent technology to monitor at the customer premises is extremely cost effective and scalable. Telchemy’s VQmon agent software is used by over 90 equipment vendors and is already pre-integrated into VoIP silicon solutions from companies such as Texas Instruments (News - Alert). A wide range of probes and analyzers that can be deployed in network operations centers and on larger customer sites is available – and almost all VoIP test equipment providers use the same VQmon software for VoIP analysis, ensuring consistency.