Network Connection

See also:

• Authentication: how to secure network connections
• Multicast DNS: by default, xpra publishes session on the network using mdns
• Data Flow: an overview of the data that flows over the network connection
• Packet Encoding: the encoding of the data exchanged over the connection
• Network Protocol: the actual packet format
• network tracker ticket: #1590

Types of connections

Xpra supports many different types of connections:

• unix domain socket connections using the bind option. From the same machine only, or via SSH (see below). When starting a server, unix domain sockets are usually created automatically for it by default
• named-pipes: MS Windows only (#1150)
• VSOCK using the bind-vsock option, for host - guest virtual machines connections, see #983
• TCP connections using the "bind-tcp" option
• UDP connections using the "bind-udp" option
• SSL connections using the "bind-ssl" option, or TCP sockets upgraded with the ssl=on option.
• websocket connections using the "bind-ws option, or TCP sockets upgraded with the html=on option
• secure websocket connections using the "bind-wss option, or TCP / websocket connections upgraded
• SSH connections: this type of connection uses a SSH as transport to connect to the unix domain socket. (forwarded using the hidden xpra sub-command "_proxy").

Notes:

• each bind option can be secured with authentication modules, in which case you probably want to enable encryption too to prevent some MITM attacks.
• the bind-XXX option may be specified more than once to bind to multiple locations, ie: multiple ports or IP addresses (IPv6 is supported).

Examples

Socket Type	Server Start Command Line Arguments	Client Command Line Argument	Optional Server Authentication Option
unix	--bind=/path/to/socket	socket:/path/to/socket	auth=module
named-pipes	n/a	named-pipe:name	auth=module
vsock	--bind-vsock=auto:1234	vsock:host:1234	vsock-auth=module
TCP	--bind-tcp=0.0.0.0:2345	tcp:127.0.0.1:2345	tcp-auth=module
SSL	--bind-ssl=0.0.0.0:443 --ssl-cert=cert.pem	ssl:127.0.0.1:443	ssl-auth=module
Websocket	--bind-ws=0.0.0.0:8080	ws:127.0.0.1:8080	ws-auth=module
Secure Websocket	--bind-wss=0.0.0.0:8080 --ssl-cert=cert.pem	wss:127.0.0.1:8080	wss-auth=module
UDP	--bind-udp=0.0.0.0:10000	udp:127.0.0.1:10000	udp-auth=module
SSH	n/a	ssh:HOST	auth=module (usually redundant)

The server arguments can be used with any server ("xpra start", "xpra shadow", "xpra upgrade", ..) and likewise the client arguments can be used with any client ("xpra attach", "xpra info", "xpra version", etc). Beware that some protocols are platform specific (unix vs named-pipes). The named-pipes and unix domain sockets currently available can be listed using the command "xpra list".

If an wiki/Authentication module is used, the client may be prompted for a password(s) when attempting to connect.

General Network Information

The performance of xpra may well be limited by your network connection speed, and will be affected by any ​bufferbloat. You can see how much bandwidth is used and how good the picture latency is using the "Graphs" tab of the "Session Info" dialog found in Xpra's system tray menu:

More network information is available in the "Session Info" dialog or via the "xpra info" command:

$ xpra info | egrep -i "network|latency"
(..)
client.latency.50p=3
client.latency.80p=3
client.latency.90p=3
client.latency.absmin=1
(..)

Investigating network performance and bottlenecks in detail is beyond the scope of this document.

For Linux systems, ​Queueing in the Linux Network Stack is recommended reading.

Xpra is very sensitive to network jitter and latency, try to ​Eliminate Bufferbloat in your Network.