There are several modules for Apache to limit the total bandwidth for each website. A well known one is mod_bw. Here are some good tutorials on how to set it up:
- http://www.gavinwill.me.uk/2012/09/limit-apache-bandwidth-with-mod_bw/
- http://linuxpoison.blogspot.tw/2012/02/setup-and-configure-bandwidth-limiting.html
- http://www.pwrusr.com/system-administration/apache-mod_bw-for-virtualhost
Here are the modules that I'm aware of which perform bandwidth limiting:
- mod_bw
- mod_bandwidth
- mod_cband
