VoIP Monitoring Manager QoS management

VoIP Monitoring Manager is a Quality of Service (QoS) monitoring/feedback tool that provides visual representation of the real-time operation of the network. All G700 Media Gateways come equipped with VoIP Monitoring Manager, which can be accessed directly or started through the Avaya MultiService Console.

VoIP Monitoring Manager provides data on QoS parameters related to VoIP quality in two forms:

• Through a client GUI application from the customer LAN or by remote access with historical as well as real-time data.
• By generating system traps/alarms to a Network Management System, whether to a local NMS station or to Avaya Services via INADS or to both,

While IP network level diagnostic and debugging tools (such as ping, netstat, tcpdump, and traceroute) are useful for diagnosing specific problems at a node or at a link, they are insufficient for monitoring RTP for per-call basis information. In addition, Avaya MultiVantage^TM provides specific QoS techniques such as Differentiated Services, and an implementation of the IEEE Ethernet level priority 802.1 p/Q standard mainly ensures call quality. Despite these QoS techniques, IP networks can still suffer due to changes in configuration, traffic load, and other factors. VoIP Monitoring Manager, which allows real-time monitoring of voice quality, is designed to identify these problems.

VoIP Monitoring Manager is technically a Real Time Control Protocol (RTCP) Monitor. Each participant in an IP based voice call experiences delay, jitter and various other problems associated transmission of real-time continuous data sent as packets over the data network. Each endpoint forwards the values that it is specifically seeing and publicizes the data through transmission of RTCP (Real Time Control Protocol) packets to the other IP call participants. The VoIP Monitoring Manager RTCP monitor receives the RTCP data sent by all participants in all calls and logs this data.

Specifically, the VoIP Monitoring Manager RTCP monitor performs these functions:

• Receives RTCP packets from network entities only that send or receive RTP-based VoIP media streams. The entities include IP endpoints, such as IP telephones and IP softphones, as well as VoIP engines running on G700 Media Gateways and Prowler boards.
• Publishes the RTCP data in the RTP MIB (plus extensions if necessary) via SNMP agent running on the server.
• Organizes that data for viewing by system administrators and services personnel.
• Provides traps/alarms related to QOS problems, based on values set by the customer.

VoIP Monitoring Manager is based on client/server architecture that allows the data collectors (servers) to be geographically distant from the front-end displays (clients). Standalone VoIP Monitoring Manager (apart from the Avaya MultiService Console) runs on Windows2000.

Each IP endpoint--IP telephone, IP softphone, G700 Media Gateway, Avaya MM760 Media Module, or Prowler--reports the following information to its specific VoIP Monitoring Manager server during each session:

• IP address
• Phone number
• Round trip time (as defined in RFC 1889)
• Delay
• Jitter
• Packet loss
• RTP payload type (codec used for a session)
• Communication server's IP Address

Delay, jitter, and packet loss measurements are calculated from the Sender Report (SR) and Receiver Report (RR). In return, the RTCP monitor returns the following information to IP endpoints:

• VoIP Monitoring Manager server IP Address
• UDP port number
• Transmission period (in seconds) (for example, x RTCP packets every y seconds)
• Whether RTCP is enabled or disabled

VoIP Monitoring Manager data display

VoIP Monitoring Manager presents a graphic display of round trip time (in ms), delay, jitter, and packet loss (as a percentage of total packets transmitted). VoIP Monitoring Manager displays real-time Quality of Service parameters of RTP sessions associated with ongoing calls:

• For single IP addresses or E.164 telephone numbers, VoIP Monitoring Manager shows real-time delay, jitter, and packet loss data for ongoing RTP session at this node.
• For single IP addresses or E.164 telephone numbers, VoIP Monitoring Manager shows delay, jitter, and packet loss data for ongoing RTP sessions at this node during a specified date and time of day range.
• For pairs of IP addresses or E.164 telephone numbers, VoIP Monitoring Manager shows real-time delay, jitter, and packet loss data for ongoing RTP sessions between the pair.
• For pairs of IP addresses or E.164 telephone numbers, VoIP Monitoring Manager shows delay, jitter, and packet loss data for RTP sessions between the pair during a specified date and time of day range.

The VoIP Monitoring Manager graphic display is similar to Avaya MultiService SMON^TM. Users can easily access QoS measurements by specifying a phone number, an IP address, or a domain name, or they can request measurements for all endpoints. Users can obtain session measurements by specifying pairs of telephone numbers, IP addresses, or domain names, or they can request measurements for all sessions. Finally, users can obtain measurements for sessions that exceed certain delay, jitter, and/or packet loss values.

Traps and alarms through VoIP Monitoring Manager

The VoIP Monitoring Manager RTCP Monitor, using the local SNMP agent, can generate traps to a trap collector specified through the Command Line Interface (CLI).

Alarm configurations

Currently, there are two configurations in which the VoIP Monitoring Manager RTCP Monitor is capable of generating traps to a trap collector:

• Communications Server Based Alarming Architecture. All Linux-based communications servers can be configured so that it serves as the trap collector and provides external alarm notification. The VoIP Monitoring Manager RTCP Monitor can be configured to generate traps to the communications server's trap collector. The trap collector receives traps from RTCP Monitor along with external network devices such as G700 Media Gateways and Avaya P330 switches. The trap collector then feeds these traps into the syslog facility.
• Network Management System Based Alarming Architecture. In networks with a Network Management System (NMS), external alarm notifications are generated by an application running on the NMS called the Network Alarm Manager (NAM).

Alarm conditions

The RTCP Monitor generates alarms on the following conditions. These types of alarms are predetermined and the conditions are configurable. The configuration includes a severity that is either "trap" or "warning".

• VoIP Call QOS alarm: Maximum delay >= X and maximum jitter >= Y and maximum packet loss >= Z. Delay, jitter and loss are averaged over a moving window of 3 reception reports to smooth out inaccuracies in individual values. The maximum averaged values over the entire call are then compared with the alarm thresholds X, Y and Z.

This alarm is generated if delay, jitter, packet loss, or any combination of the three exceed the specified values. If a single call triggers multiple alarms, only the first alarm is generated, and subsequent alarms are ignored.

• VoIP System QOS alarm: Total # of voip-callqos alarm warnings in the entire RTCP Monitor >= M over time interval T. If T is zero then the alarm will be generated as soon as the total # of warnings reaches the threshold M. If T is non-zero then the alarm will be checked every interval starting at the time the monitor is run.

This alarm is generated if the total number of voip-callqos alarms recorded by the RTCP monitor exceeds the specified number within the specified time period.

• VoIP Terminal QOS trap: Total # of voip-callqos alarms from the same IP endpoint with status = "warning" >= N over time interval T. If T is zero then the alarm will be generated as soon as the total # of warnings reaches the threshold M. If T is non-zero then the alarm will be checked every interval starting at the time the monitor is run.

This alarm is generated if the total number of voip-callqos alarms from one IP endpoint exceeds the specified number of a specified time period.

VoIP Monitoring Manager administration

VoIP Monitoring Manager is administered using the IP Network Region SAT screens within the DEFINITY� Administration process. For administration procedures, refer to the most recent SAT Administration documents.