The Bridge Traffic Analyzer is a tool that allows administrators to obtain traffic data on their Cisco Bridge units to determine:
- total size of messages sent
- number of messages sent
- which servers messages have come from or gone to
- how long it takes for messages to arrive at their destinations
- how many analog ports are in use for message transport
- How many failures were there sending and receiving messages between various nodes
Inbound vs. Outbound Messages
The Bridge server logs all message traffic activity from the perspective that inbound messages are those that come from Octel nodes to the Bridge and are then delivered to the Cisco Unity server(s). Outbound messages are those that go from Cisco Unity servers to the Bridge, and then are delivered to Octel nodes. The Bridge Traffic Analyzer uses this convention throughout its reports.
It is important to note that Cisco Unity sends and receives messages to and from the Bridge server via IP, which is very quick. The Octel nodes, on the other hand, send and receive messages to the Bridge via analog voice lines, which is considerably slower, and is dependant on a potentially limited number of available analog line resources. For this reason, the outbound message traffic is typically the more interesting item to look at in these reports. In fact, the Message Latency report does not even offer the option to view inbound messages, because typically there is very little if any delay between the time a message arrives on the Bridge to the time it is delivered via IP to the Unity node. The remaining three reports offer the option of viewing inbound traffic information, though the default is to show only outbound traffic information.
Port Availability Report
The Port Availability report does not take any parameters; instead, it processes analog port activity on the log for the entire day. The purpose of this report is to show how many analog ports on the Bridge are being used to communicate to Octel nodes at any given time of the day. The report shows a bar for each minute of the day, indicating how many ports are in use and/or how many ports are available to take calls. You can choose to show busy ports, ports available to take calls, or both, by checking the checkboxes at the top of the report form.
The Port Availability report can show the entire day, or you can use the Zoom menu to show a 12-hour, 4-hour, or 1-hour chunk of the day. The following screen shot shows an hour of port activity from 6:15 pm to 7:15 pm (all times are shown in 24-hour clock format). The report was set up with the default mode of showing the number of analog ports available to take or make calls on the Bridge server. Note that as the bars get closer to 0, the number of ports available for processing new messages goes to 0. This report format makes it easier to see when port resources are getting critically low. The Bridge does contain logic to terminate message delivery calls in order to free up analog ports when the number of available ports approaches 0, therefore making sure that ports are available to handle inbound calls from Octel nodes. However, heavy inbound message traffic from Octel nodes through to Unity nodes can chew through all the available ports.
Message Queue Activity Report
The Message Queue Activity report shows how many messages and how much data is passing through the inbound and outbound message queues on the Bridge server. Inbound messages are those traveling from Octel nodes to the Bridge via analog lines and then to the Cisco Unity servers via IP; outbound messages are those traveling from Cisco Unity to the Bridge via IP and then to Octel nodes via analog lines.
Outbound message traffic is the more interesting item to analyze, because this is where bottlenecks may occur. Cisco Unity can quickly route messages to and from the Bridge via IP. It is the ability of the Bridge to get messages out of the queue and to the Octel nodes that may be a problem. Therefore, it is not likely that the inbound message queue will grow very large, but the outbound message queue can back up if port resources are not sufficient to handle the load.
The following screen shot shows 4 hours of activity on a load test and the outbound message queue size over all. You can see that it is staying pretty steady between 25 and 30 megs in size, which is a good, healthy trend.
- The Bridge Traffic Analyzer requires version 2.1 or later of the Cisco Unity Bridge. It is not dependant on the Cisco Unity version, because the reports generated are entirely based on logging output on the Bridge unit.
- The Bridge Traffic Analyzer can be run on or off the Cisco Unity server. The only necessity is access to the logging directory on the Bridge server. However, if possible, it is recommended that you not run the tool on the Cisco Unity server, to avoid adding additional overhead.