I need some clarification for window size.
I know the Window Size in a TCP packet indicates the size of the receive buffer of the host.
Is this the receive buffer for a single TCP stream or for all streams?
As an example, a web server will have thousands if not more connections.
So the Window size in the TCP window, is this the receive window for all connections or just the connection between a single client and server.
Window size is a per stream setting.
Different destinations may benefit form different sizes.
Next to the initial Window Scale, other setting can be negotiated during the TCP handshake, like Maximum Segment Size (MSS) and Selective Acknowledgment (SACK). Described at RFC 9293, but Wikipedia may be more readable.
A big window size can be negotiated but the actual memory allocated by the OS can be smaller initially, and increased during the session when necessary. This is to keep the total memory usage for all streams low.
Asked: 2024-12-27 12:12:03 +0000
Seen: 32 times
Last updated: Dec 27 '24
