Assumptions

Since test bed was created for emulation of Internet environment in lab, we made the following assumptions:

1. In IP packet forwarding mechanism, it was assumed that each IP packet will contain TCP header, i.e., IP packets are not fragmented. In Linux, higher layers indeed use maximum transfer unit information so that packets do not need fragmentation and reassembly in LAN environment.

2. To avoid any central entity like router from becoming bottleneck, packet losses and delays in one direction are introduced by front node when packets reach to web servers and by clients themselves when packets arrive from servers for them.

3. We have implemented one way distributed packet rewriting for request distribution at front nodes and all servers have to rewrite incoming IP packets for HTTP connections. We assume that overhead of rewriting incoming IP packets for re-injection in TCP/IP stack with aliased secondary IP address is negligible.