# Session ID

A proxy session ID is an arbitrary identifier that the client adds to its proxy username so that the gateway groups requests into a session and routes all of them through the same exit IP. Any value works; the gateway only compares identifiers. Using a new identifier is the simplest way to force a new exit, and using one identifier per account, basket or task is how parallel sessions are isolated from each other.


## Choosing identifiers

- Random and unique per logical session: a short hash of the account name or task id works well.
- Never reuse an identifier across unrelated jobs, or they will share an exit and a reputation.
- Keep them short and alphanumeric; providers cap the length and the character set.


## Identifier scope

A session id is scoped to your account and to the location parameters used with it: the same id with `-cc-de` and with `-cc-fr` are two different sessions. It is also scoped to the gateway: residential and mobile keep separate session tables.


## How it works at ProxShift

On ProxShift the parameter is -sid-, up to 32 characters (a-z, 0-9), combined with -ttl- for the lifetime. Omit it and every connection rotates.

Source: https://proxshift.com/glossary/session-id