the latency across the network is dependent on the distance the packets
have to travel, our thresholds
are set to be distance sensitive (based on the speed of light in fiber).
The distances used are direct (crow-flies) miles.
Connect Success Rate
It is the ability of the user client's dialup modem and the network modem
to connect at any modem speed.
The current average for Modem Connect Success Rate shown on the front
page of the site are averaged
over 24 hours over all Points of Presence (PoPs).
is the overall availability of the network averaged over the month.
Network Jitter or delay variation is a measure of the variablility for
a series of one-way latency measurements.
are the averages for each of the previous three months over all city-pairs
for round trip delay and loss.
We also present the backbone availability for the month.
(or delay) is the round-trip time for a small data packet to travel between
two end points (source
and destination city-pairs) in the network. Latency affects one's perception
of the response time of the network.
City-pair latency statistics are updated every 15 minutes. The current
average for Continental U.S. Network
connections shown on the home page of the site is the average over all
relevant city-pair latency values
for the current 15-minute update. When data is unavailable, no value is
is the percentage of packets lost in a data transaction. The opposite
of loss, data delivery is defined
as 100 minus the percentage of packet loss and is the percentage of successfully
The measurement is a round trip one, made by counting the packets sent
between two cities that do
not return. City-pair loss statistics are updated every 15 minutes. The
current average for Network Loss,
shown on the home page of the site is the average over all relevant city-pair
loss percentages for
the current 15-minute update. When data is unavailable, no value is shown.