Monitoring the PBX

Christian Stredicke
CEO of Vodia Networks

It is amazing what has happened to network monitoring.

In the good old days, SNMP was the protocol of choice for monitoring network elements. SNMP has gone through a long history, we remember SNMPv2 and SNMPv3 and all those long codes to read out the information that we are looking for. For example, 1.3.6.1.4.1.25060.1.13 is used to figure out how many call legs the system currently has. See http://vodia.com/doc/snmp for the list that the PBX supports.

SNMP has its problems. First of all, like all UDP-based protocols, packet loss and repetition makes it a pain to program. And then SNMP is not very firewall friendly, because of the network translation issues introduced by the shortage of IP addresses and the flourishing firewall business. Authentication was obviously fixed in SNMPv3; however the standards used there did not really make it into the mainstream like we see it today with anything based on HTTPS.

To be honest, if SNMP disappears from the Internet, we will not cry many tears.

It seems that New Relic understands this very well and has build a service around the reporting. Like so many other web services, it is just using HTTPS for the reporting. Obviously the model that the server gets polled every so-and-so seconds does not work any more when most servers are operating behind firewalls; so the reporting has been turned around. Now it is up to the server to report numbers.

We went ahead and added the New Relic API to the PBX. All that needs to be entered is the API key that users get from their web site; then the PBX will start reporting. What is currently reported is the data seen from the status screen, including CPU load and registrations. We did not figure out if a MOS graph like we have it can be reported in any way. Also, looking at the SNMP sensors that we have, we might add more data back also into the New Relic interface.

The new feature has not been released yet. We include it in the day-to-day build of 5.5.1. As always you are more than welcome to try it out and give feedback on how this is going.