Nortel Networks WEB OS 212777 - Manual (Page 423)

Web OS 10.0 Application Guide
Chapter 16: Persistence n 423
212777-A, February 2002
Using Cookies
Cookies are strings passed via HTTP from servers to browsers. Based on the mode of opera-
tion, cookies are inserted by either the Web switch or the server. After a client receives a
cookie, a server can poll that cookie with a GET command, which allows the querying server
to positively identify the client as the one that received the cookie earlier.
The cookie-based persistence feature solves the proxy server problem and gives better load
distribution at the server site. In the Web switch, cookies are used to route client traffic back to
the same physical server to maintain session persistence.
Using SSL Session ID
The SSL session ID is effective only when the server is running SSL transactions. Because of
the heavy processing load required to maintain SSL connections most network configurations
use SSL only when it is necessary. Persistence based on SSL Session ID ensures completion of
complex transactions in proxy server environments. However, this type of persistence does not
scale on servers because of their computational requirements.