SYNOPSIS
UDP is unreliable protocol transport of data over IP networks. UDP support both unicast and multicast communication.
DESCRIPTION
UDP transport can only be used with the ZMQ_RADIO and ZMQ_DISH socket types.
ADDRESSING
A ØMQ endpoint is a string consisting of a transport://
followed by an
address. The transport specifies the underlying protocol to use. The
address specifies the transport-specific address to connect to.
For the UDP transport, the transport is udp
.
The meaning of the address part is defined below.
Binding a socket
With 'udp' we can only bind the 'ZMQ_DISH' socket type.
When binding a socket using _zmq_bind()_ with the 'udp'
transport the 'endpoint' shall be interpreted as an 'interface' followed by a
colon and the UDP port number to use.
An 'interface' may be specified by either of the following:
* The wild-card `*`, meaning all available interfaces.
* The name of the network interface (i.e. eth0, lo, wlan0 etc...)
* The primary address assigned to the interface, in its numeric representation.
* Multicast address in its numeric representation the socket should join.
The UDP port number may be specified a numeric value, usually above
1024 on POSIX systems.
Connecting a socket
With udp we can only connect the ZMQ_RADIO socket type. When connecting a socket to a peer address using zmq_connect() with the udp transport, the endpoint shall be interpreted as a peer address followed by a colon and the UDP port number to use.
A peer address may be specified by either of the following:
-
The IPv4 or IPv6 address of the peer, in its numeric representation or using its hostname.
-
Multicast address in its numeric representation.
EXAMPLES
// Unicast - UDP port 5555 on all available interfaces
rc = zmq_bind(dish, "udp://*:5555");
assert (rc == 0);
// Unicast - UDP port 5555 on the local loop-back interface
rc = zmq_bind(dish, "udp://127.0.0.1:5555");
assert (rc == 0);
// Unicast - UDP port 5555 on interface eth1
rc = zmq_bind(dish, "udp://eth1:5555");
assert (rc == 0);
// Multicast - UDP port 5555 on a Multicast address
rc = zmq_bind(dish, "udp://239.0.0.1:5555");
assert (rc == 0);
// Same as above but joining only on interface eth0
rc = zmq_bind(dish, "udp://eth0;239.0.0.1:5555");
assert (rc == 0);
// Same as above using IPv6 multicast
rc = zmq_bind(dish, "udp://eth0;[ff02::1]:5555");
assert (rc == 0);
// Connecting using an Unicast IP address
rc = zmq_connect(radio, "udp://192.168.1.1:5555");
assert (rc == 0);
// Connecting using a Multicast address
rc = zmq_connect(socket, "udp://239.0.0.1:5555);
assert (rc == 0);
// Connecting using a Multicast address using local interface wlan0
rc = zmq_connect(socket, "udp://wlan0;239.0.0.1:5555);
assert (rc == 0);
// Connecting to IPv6 multicast
rc = zmq_connect(socket, "udp://[ff02::1]:5555);
assert (rc == 0);
AUTHORS
This page was written by the ØMQ community. To make a change please read the ØMQ Contribution Policy at http://www.zeromq.org/docs:contributing.