HTTP/1.0 Performance Issues

• HTTP/1.0 opens a new TCP connection for every single transaction. For example, if a Web page contains 10 <img ...> images, HTTP/1.0 must open a total of 11 TCP connections -- one for the original page, and 10 for the images. Problems which arise from this include:
   
  
  • There can be a moderately long overhead in initial connection establishment due to round-trip delays.
  • TCP initiates connections using the so-called "slow start" algorithm. This is necessary for proper operation, but is very inefficient for short transfers -- TCP typically takes 10 to 20KB of transferred data to get "up to full speed". Both of these can cause HTTP/1.0 browsers to seem really slow.
  
   
  
• TCP is required to maintain "state" information about closed connections for 240 seconds, to ensure that stray packets from old connections won't be interpreted as valid data by a later connection. When a server is handling a large number of connections, this can require huge buffer space, and is very inefficient.
   
  
• HTTP/1.0 has very limited support for caching.