Bandwidth Utilization

[Mohamed Sobair]

Hi All,

I have an Internet link from ISP with 1MB connection Speed, when I download huge files from different web servers I got less than the mentioned speed unless downloading 3 or 4 sessions then I got by calculating the all my full speed, However, when an engineer gets access to my vlan on the ISP premises he could get the full speed by downloading one session...

Is it Normal behaviour, or theremight be some thing wrong? As my ISP gave me an access to my bandwidth utilization graph & I can see that my bandwidthis fully utilized , but I can't get it from single download session?

please advice me on the above,

Thanks in Advance,

[pkhatri]

Generally, what you are describing is very true for most secnarios. A single TCP session is not able to utilise the full bandwidth of a link due to the effects of TCP slow-start and congestion avoidance. When you have multiple such sessions, the averaging of the 'saw-tooth' graph created by each session results in a better utilisation of the link.

To some extent, it also depends on the implementation of the TCP stack on the clients/servers being used. That is potentially a reason you engineer managed to get full bandwidth across the link over just a single session.

Paresh