VoIP Spear Blog: News & Noise

ICMP vs UDP

VoIP Spear servers work by pinging our users' endpoints. Ping is a nearly ubiquitous network tool that is used to test whether or not a computer/device is reachable across the Internet.

One problem with using ping is that ping uses the ICMP protocol while VoIP uses UDP. It was for this reason that we used UDP for testing when we first started developing VoIP Spear. We were aiming to support two types of testing -- basic testing would use ping/ICMP and advanced testing would use UDP. We envisioned that basic testing would be perfect for novice users because it's so easy to set up while advanced testing, on the other hand, would be more accurate and perfect for our advanced users.

After a few months, we realized two things:

1. Advanced testing would require users to run a VoIP Spear software app (which we called a UDP mirror because it just bounced back UDP packets to our servers). This requirement would mean that our advanced tests could only be run on computers capable of running the software, thus excluding many VoIP phones and other endpoints. In addition, the requirement to run/install software would have meant much lower adoption rates because it's a pain to install software (especially software like the UDP mirror which needs to be running all the time on users' computers).
2. The results from our basic tests (using ICMP/ping) were just as accurate as the UDP tests.

So we decided to change course slightly and only offer ping/ICMP testing. It has meant that VoIP Spear is easy to use rather than a challenge. This decision also forced us to implement testing from multiple servers, something which lends an even greater degree of accuracy to our tests.

We've been delighted with the decision so far.