It seems that almost weekly I am being asked “How can I tell how many calls are actually going on at any one point”". The driving force behind these questions recently has been the push to SIP. With the economy being what it is everyone is looking for cost savings and SIP is one of those things that not only saves money but in most cases saves a lot of money.
With traditional telephony circuits you size the number of talk-paths based off the physical location. With SIP the physical location boundary is removed and instead you size based off total con-current talk-paths needed. This is the source of most savings. For example if you have 10 offices each with their own PRI you have 230 talk-paths. The chances that all 10 offices max their PRIs out at one time is very slim. Instead you might find that only a fraction of those might be in use all at the same time.
So again the question becomes what is my actual usage? The first stop for most customers is the telephony circuit provider. They get mixed results there. Typically they are not left feeling comfortable with what they are told and instead would like to get their own numbers. This is where I typically get tasked to explain to them how to get this data.
When using Cisco CallManager there is no easy way to get this data unfortunately. While we can get this data we have to jump through some hoops. First lets cover the list of gotchas:
- You can’t run a report and collect historical data.
- You have to capture this data on a per gateway basis and then merge the data together based off time interval
- You can only capture 6 gateways per PC. You most likely will have to run multiple copies of the software to capture the data across all your gateways.
So how do we accomplish this? Follow these steps:
- Download and install Cisco Real Time Monitoring Tool. It can be found under Application/Plugins in the Communications Manager Web Interface.
- Once this is installed point it to the subscriber that the gateway is registered too and log in with an administration account.
- Click on Performance
- From this point if you want to look at an H323 gateway then expand Cisco H323 and select CallsActive, if MGCP expand Cisco MGCP Gateways and select PRIChannelsActive or FXOPortsActive.
- After Selecting this information you will be prompted to select a gateway. Select the gateway you wish to monitor and click add
- At this point you should have between 1 and 6 gateways shown on your screen. Click on the first gateway (A box should appear around the graph to show you it is highlighted). Right click and click Start Counter(s) Logging. Enter a unique name and click Ok.
- Repeat for all other gateways.
At this point the gateways are generating six CSV files found under your user directory in the .jrtmt/logs folder. You can get the exact location shown to you when the dialog box to enter a filename is displayed. You will most likely have to repeat this on multiple PCs until you are collecting logs on all your PCs
What will result is a series of CSV files. Each time there is at least one call going on a row is added to the log. The gateways are polled every 10 seconds and the chances are that all the PCs will not have the exact same polling time. As such you will need to figure out what your polling window will be. I typically recommend rounding down or up to the base tens (10, 20, 30, etc…). This will generate the picture of gateway utilization and concurrent talk-paths in use across all your gateways.
Like I said it wasn’t very pretty but it will get you accurate data.