In this study we present network-wide measurements of Round- Trip-Time (RTT) from an operational 3G network, separately for GPRS/EDGE and UMTS/HSxPA sections. The RTTs values are estimated from passive monitoring based on the timestamps of TCP handshaking packets. Compared to a previous study in 2004, the measured RTT values have decreased considerably. We show that the network-wide RTT percentiles in UMTS/HSxPA are very stable in time and largely independent from the network load. Moreover, we present separate RTT statistics for handsets and laptops, showing that they are very similar in UMTS/HSxPA but not in GPRS/EDGE. During the study we identify a problem with the RTT measurement methodology due to early retransmission of SYNACK packets by some popular servers.
Network-wide measurements of TCP RTT in 3G
RICCIATO, FABIO;
2009-01-01
Abstract
In this study we present network-wide measurements of Round- Trip-Time (RTT) from an operational 3G network, separately for GPRS/EDGE and UMTS/HSxPA sections. The RTTs values are estimated from passive monitoring based on the timestamps of TCP handshaking packets. Compared to a previous study in 2004, the measured RTT values have decreased considerably. We show that the network-wide RTT percentiles in UMTS/HSxPA are very stable in time and largely independent from the network load. Moreover, we present separate RTT statistics for handsets and laptops, showing that they are very similar in UMTS/HSxPA but not in GPRS/EDGE. During the study we identify a problem with the RTT measurement methodology due to early retransmission of SYNACK packets by some popular servers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
