How to Implement VOIP detection and real-time monitoring

Some people think that IP phones are just another application running on the data network. However, imagine this situation: the quality of VoIP calls is getting worse and worse, and even the entire enterprise IP phone system stops running. Terrible? Pay attention to VoIP and add specialized VoIP tools for your network management platform.

Recently, Network World has evaluated a series of emerging products, all of which can be attributed to VoIP analysis tools. They help VoIP network administrators perform proactive monitoring and eliminate problems in the system to ensure the continuous operation of IP phones.

A total of seven vendors responded to the test invitation: Agilent, Brix, ClearSight, Fluke, Touchstone, Viola, and WildPackets. After tests, ClearSight's analysis tool has gained the highest rating for its easy-to-use characteristics and outstanding ability to analyze VoIP protocols. Fluke Optview can capture sufficient VoIP call information, but it is a little troublesome to use. While competing for the third place, Agilent, Touchstone, and WildPackets all provide more complete analysis capabilities than private environments in SIP.

These tools are almost all PC-based professional application software, and some also provide probe hardware. Many of them are plug-ins used by the vendor's network data analyzer to analyze VoIP.

Test Method

Connect the VoIP analysis tool to four ip pbx systems. They are: EADS telecommunications Nexspan L systems using private protocols, Mitel SX-200 ICP, both using private protocols and supporting SIP's NEC Univerge 7000, and PingTel SIPxchange that only supports SIP but supports a lot.

In the test environment, two subnets are configured to simulate the headquarters and a branch. The two subnets are interconnected through the Cisco router and the Extreme switch. The Hurricane IP Network Simulator of PacketStorm is used to simulate WAN links. The simulator simulates the real environment and adds latency, jitter, packet loss, and other features on the link.

In the subnet where the headquarters is located, the tester configures An Image Port for each VoIP analysis tool. However, Brix and Viola products are also connected to the two ends of the WAN link, which can evaluate the performance of the link.

More than eight IP phones were used in the test to generate real VoIP calls between the headquarters and branches. Some calls are generated within the subnet of the headquarters. A maximum of four IP phones can be called at the same time. Before, after, or during a session, the tested analysis tool is used to check the call status. Use them to display call initialization and setup, signaling, and any performance parameters related to actual VoIP calls.

Protocol Problems

The tester reminded users that these VoIP analysis tools are generally oriented to specific VoIP protocol environments. It is difficult to correctly resolve the packet order of different call control protocols, because the packets of each protocol are quite different.

The tester took two months to test each tool in four different VoIP environments, including three private protocols and two SIP-based solutions. These testing tools differ significantly in the ability to monitor and track VoIP behavior in comparison with the private environment. Only ClearSight And Fluke tools have good performance in both cases. However, other tools can analyze some of the VoIP traffic in different protocol environments. This is because the actual VoIP session is composed of two-way RTP (Real-Time Transport Protocol) streams encapsulated in UDP packets, even if the ip pbx uses private signaling, the RTP stream generated during telephone conversations is easy to identify and decode for analysis tools.

Real-time VoIP monitoring

Tests focus on the performance of these products during real-time VoIP monitoring. Whether the following information can be obtained based on the score:

◆ VoIP call control (call initiation and establishment of signaling ).

◆ Current VoIP call status.

◆ Details of the current VoIP call (caller's destination, used voice codecs, etc ).

◆ Bandwidth consumed by the current VoIP call.

◆ IP addresses of key VoIP nodes and endpoints (call controllers, gateways, and IP phones ).

◆ Latency, jitter, and packet loss of VoIP calls between two distributed sites.

ClearSight has performed well in the previous several research points, and is the undisputed winner in tracking VPC call control and reporting bandwidth consumed by VoIP calls.

Clear and clear

It is not enough for a VoIP analysis tool to accurately track user information. It must also be able to view data in a clear and intuitive manner. In terms of this critical availability and navigability, ClearSight gets first, and the VoIP stream is displayed in a log-type table. You can select any table item and further explore more details. The displayed images are clear and readable. The summary tab displays the total bandwidth and traffic. You can capture and replay any VoIP stream with only one click.

The tester also evaluated the product report function. In addition, the unique features of some products are also shown. For example, ClearSight has the ability to directly decode VoIP calls transmitted on a Wi-Fi wireless network.

1. VoIP security monitoring is required
2. Test VoIP call Quality