RARPSL
join:1999-12-08
Suffern, NY
| reply to TKJunkMail
Re: Upstream channel bonding!
said by TKJunkMail  :You are right expecting an upload limit having an effect on how fast you can download. But 2 mbps upload(if no other traffic using the upload like a P2P app) would allow an FTP download for example to reach the full download capacity. TCP/IP is a 2-way communications protocol. To be able to download, you have to upload acknowledgements of the successful receipt of the downloaded packets. There are ways to reduce the need for the upload bandwidth load but even that has a limit (at least until IPv6 is used which allows larger [AKA Jumbo] packets and larger/sliding transmit windows). Each 1500 packet with download data needs a upload packet to say that the downloaded packet has arrived. That uploaded packet controls how fast you can download since you will not be eligible for more downloaded data until you acknowledge the receipt of the "in flight"/prior packets. The ACK packets tend up be small and the major part is the Headers/Overhead not the actual payload content. Thus if you saturate your upload session with the small ACK packets, you can not download any faster. There is also the case where YOU are doing the uploading (such as SENDING not RECEIVING Email) where you are being lock-stepped by maxing out the upload channel. |
