The Importance of Internet Latency Measurements
19/10/2022
Anyone who has ever worked in both IT and telecommunications is very familiar with the use of ping and trace tests to perform an initial troubleshooting of private networks, most often for the purpose of finding out whether a specific service or application is down. However, the fact that ping and trace tests can be used to validate the performance of full Internet services remains unknown to most. At the network protocol level, ping tests are based on the Internet Control Message Protocol (ICMP) defined in RFC792 and basically shows us the “roundtrip” response time it takes an IP packet to go from a source to a destination network. Just as well known, trace tests are also part of the IP protocol suite and allow seeing the hops (or networks) that an IP packet uses to go from a source to a destination network.
Published in 2003, International Telecommunications Union (ITU) Recommendation G.114 considers latency measurements for voice applications. This recommendation is almost 20 years old and focuses mostly on the development of VoIP applications, which became very fashionable 20 years ago after the birth of the Internet. According to this recommendation, a “one-way-delay” ranging between 150 and 400 msec is acceptable for the proper performance of VoIP applications. It should be noted that ping tests provide round-trip latency, so I would personally define a roundtrip delay between 75 and 200 msec as an acceptable latency range for VoIP applications.
In early 2021, LACNIC published a study titled “Connectivity in the LAC Region in 2020” which analyzes Internet latency times in the various countries of Latin America using ping tests from the different countries. In the case of Panama, the results obtained by LACNIC caught our attention. Measurements for the tests originating in Panama to destinations outside of the country averaged a 183 msec roundtrip delay, the measurements for tests with their destination in Panama averaged a 171 msec roundtrip delay, and the measurements for tests originating in Panama and with their destination also in Panama averaged an 87 msec roundtrip delay. At first glance these response times appear to be acceptable for VoIP applications. However, technology has evolved and today the Internet is used for much more than phone calls and video conferencing. In the last 20 years, the use of new Internet-based technologies requiring what is currently known as “Low-Latency” applications has grown exponentially, among them the Internet of Things (IoT), Cloud Computing, SD-WAN, Smart Cities, Autonomous Vehicles, Virtual Reality, and Augmented Reality. All these applications demand extremely low response times when connected to the full Internet, namely, roundtrip delays as low as 10 to 40 msec or even lower. Thus, at second glance the latency times determined by the study conducted by LACNIC for Panama at the start of 2021 no longer seem so acceptable for the future implementation of these new technologies. The results of the tests with their origin and destination in Panama —an 87msec roundtrip delay— particularly caught our attention: for a country as small as Panama, we found these response times to be quite high. This study shows the need to optimize the interconnection between the different operators in Panama in order to successfully implement next generation technologies such as IoT, Smart Cities, Cloud Computing, and many others
On the plus side, the study conducted by LACNIC provided us with a starting point from which to make future measurements and validate our progress over time. Hence the importance of Internet latency measurements.