Ice Docs

Endpoint Syntax

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Ice uses endpoints for two similar but distinct purposes:

  1. In a client context (that is, in a proxy), endpoints determine how Ice establishes a connection to a server.
  2. In a server context (that is, in an object adapter's configuration), endpoints define the addresses and transport protocols over which new incoming connections are accepted.

This page presents the addressing component of endpoints, as well as the transport protocols and their options.

endpoint : endpoint

An endpoint list comprises one or more endpoints separated by a colon (:).

An endpoint has the following format:

transport option

transport can be any of the Ice transport protocols described on this page (tcp, ssl, udp etc.), or default. When default is used, it is replaced by the value of the Ice.Default.Protocol property (default protocol means default transport protocol). If an endpoint is malformed, the application receives a ParseException. If the transport of an endpoint is not registered with the communicator, an object adapter throws ParseException when it parses its endpoints, whereas Ice drops the endpoint from a stringified proxy.

host : hostname | x.x.x.x | ":x:x:x:x:x:x:x"

Ice supports Internet Protocol (IP) versions 4 and 6 in all language mappings.

Support for these transport protocols is configured using the properties Ice.IPv4 and Ice.IPv6 (both enabled by default).

In the endpoint descriptions below, the host parameter represents either a host name that is resolved via the Domain Name System (DNS), an IPv4 address in dotted quad notation, or an IPv6 address in 128-bit hexadecimal format and enclosed in double quotes. Due to limitation of the DNS infrastructure, host and domain names are restricted to the ASCII character set.

The presence (or absence) of the host parameter has a significant influence on the behavior of the Ice runtime. The table below describes these semantics:

ValueClient SemanticsServer Semantics
None
If host is not specified in a proxy, Ice uses the value of the Ice.Default.Host property. If that property is not defined, outgoing connections are attempted over loopback addresses.
If host is not specified in an object adapter endpoint, Ice uses the value of the Ice.Default.Host property. If that property is not defined, the adapter behaves as if the wildcard symbol * was specified (see below).
Host name
The host name is resolved via DNS. Outgoing connections are attempted to each address returned by the DNS query.
noteYou should avoid using DNS names in object adapter endpoints. You should avoid using DNS names in object adapter endpoints. The host name is resolved via DNS, and the object adapter listens on the network interfaces corresponding to each address returned by the DNS query.
IPv4 address
An outgoing connection is attempted to the given address.
The object adapter listens on the network interface corresponding to the address.
IPv6 address
An outgoing connection is attempted to the given address.
The object adapter listens on the network interface corresponding to the address.
0.0.0.0 (IPv4)
A "wildcard" IPv4 address that causes Ice to try all local interfaces when establishing an outgoing connection.
The adapter listens on all IPv4 network interfaces (including the loopback interface), that is, binds to INADDR_ANY for IPv4.
"::" (IPv6)
A "wildcard" IPv6 address that causes Ice to try all local interfaces when establishing an outgoing connection.
Equivalent to * (see below).
* (IPv4, IPv6)
Not supported in proxies.
The adapter listens on all network interfaces (including the loopback interface), that is, binds to INADDR_ANY for the enabled transport protocols (IPv4 and/or IPv6).

When IPv4 and IPv6 are enabled, an object adapter endpoint that uses an IPv6 (or * wildcard) address can accept both IPv4 and IPv6 connections.

Java's default network stack always accepts both IPv4 and IPv6 connections regardless of the settings of Ice.IPv6. Thus, in Java, an object adapter endpoint that uses the IPv4 wildcard will accept both IPv4 and IPv6 connections. You can configure the Java runtime to use only IPv4 by starting your application with the following JVM option:

Shell
java -Djava.net.preferIPv4Stack=true ...

tcp -h host -p port -t timeout -z --sourceAddress addr

The TCP transport protocol is a built-in transport protocol: it's always available.

A tcp endpoint supports the following options:

OptionDescriptionClient SemanticsServer Semantics
-h host
Specifies the host name or IP address of the endpoint. If not specified, the value of Ice.Default.Host is used instead.
See IP Address Syntax.
See IP Address Syntax.
-p port
Specifies the port number of the endpoint.
Determines the port to which a connection attempt is made (required).
The port will be selected by the operating system if this option is not specified or port is zero.
-t timeout
Specifies the endpoint timeout in milliseconds.
The value for timeout must either be infinite to specify no timeout, or an integer greater than zero representing the timeout in milliseconds. Endpoint timeouts are deprecated. They have no effect as of Ice 3.8.
The value for timeout must either be infinite to specify no timeout, or an integer greater than zero representing the timeout in milliseconds. Endpoint timeouts are deprecated. They have no effect as of Ice 3.8.
-z
Specifies bzip2 compression.
Determines whether requests are compressed during sending.
Determines whether compression is advertised in proxies created by the adapter.
--sourceAddress ADDR
Specifies the source address used by the connection.
The value for ADDR must be a numeric IPv4 or IPv6 address. If this option is not specified, it defaults to the value of Ice.Default.SourceAddress.This option allows to specify the source address set in the IP packet. It doesn't necessarily imply that the operating system will use the network interface matching this IP address to send out the IP packet.
Not supported

udp -h host -p port -z --ttl TTL --interface INTF --sourceAddress addr

The UDP transport protocol is a built-in transport protocol that is always available.

If you’re using C++ with a static build, you need to load this transport explicitly as follows:

C++
Ice::InitializationData initData;
initData.properties = Ice::createProperties(argc, argv);
initData.pluginFactories = {Ice::udpPluginFactory()};


Ice::CommunicatorPtr communicator = Ice::initialize(initData);

A udp endpoint supports either unicast or multicast delivery; the address resolved by host argument determines the delivery mode. To use multicast in IPv4, select an IP address in the range 233.0.0.0 to 239.255.255.255. In IPv6, use an address that begins with ff, such as ff01::1:1.

A udp endpoint supports the following options:

OptionDescriptionClient SemanticsServer Semantics
-h host
Specifies the host name or IP address of the endpoint. If not specified, the value of Ice.Default.Host is used instead.
See IP Address Syntax.
See IP Address Syntax.
-p port
Specifies the port number of the endpoint.
Determines the port to which datagrams are sent (required).
The port will be selected by the operating system if this option is not specified or port is zero.
-z
Specifies bzip2 compression.
Determines whether requests are compressed during sending.
Determines whether compression is advertised in proxies created by the adapter.
--ttl TTL
Specifies the time-to-live (also known as "hops") of multicast messages.
Determines whether multicast messages are forwarded beyond the local network. If not specified, or the value of TTL is -1, multicast messages are not forwarded. The maximum value is 255.
N/A
--interface INTF
Specifies the network interface or group for multicast messages (see below).
Selects the network interface for outgoing multicast messages. If not specified, multicast messages are sent using the default interface.
Selects the network interface to use when joining the multicast group. If set to * or not specified, the group is joined on all the local network interfaces.
--sourceAddress ADDR
Binds outgoing socket connections to the network interface associated with ADDR.
The value for ADDR must be a numeric IPv4 or IPv6 address. If this option is not specified, it defaults to the value of Ice.Default.SourceAddress.This option allows to specify the source address set in the IP packet. It doesn't necessarily imply that the operating system will use the network interface matching this IP address to send out the IP packet.This feature is not supported on Universal Windows (UWP).
Not supported

When host denotes a multicast address, the --interface INTF option selects a particular network interface to be used for communication. The format of INTF depends on the language and IP version:

  • C++ and .NET INTF can be an interface name, such as eth0, or an IP address. If using IPv6, it can also be an interface index. Interface names on Windows may contain spaces, such as Local Area Connection, therefore they must be enclosed in double quotes.
  • Java INTF can be an interface name, such as eth0, or an IP address. On Windows, Java maps interface names to Unix-style nicknames.

ssl -h host -p port -t timeout -z --sourceAddress addr

An ssl endpoint supports the same options as for tcp endpoints.

ws -r resource -h host -p port -t timeout -z --sourceAddress addr

A ws (WebSocket) endpoint supports all tcp endpoint options in addition to the following:

OptionDescriptionClient SemanticsServer Semantics
-r resource
A URI specifying the resource associated with this endpoint. If not specified, the default value is /.
The value for resource is passed as the target for GET in the WebSocket upgrade request.
The web server configuration must direct the given resource to this endpoint.

wss -r resource -h host -p port -t timeout -z --sourceAddress addr

A wss (Secure WebSocket) endpoint supports all ssl endpoint options in addition to the following:

OptionDescriptionClient SemanticsServer Semantics
-r resource
A URI specifying the resource associated with this endpoint. If not specified, the default value is /.
The value for resource is passed as the target for GET in the WebSocket upgrade request.
The web server configuration must direct the given resource to this endpoint.

bt -a addr -u uuid -c channel -t timeout -z --name name bts -a addr -u uuid -c channel -t timeout -z --name name

The Bluetooth transport protocol is provided by a separate IceBT plug-in.

The IceBT transport plug-in enables bt endpoints and TLS-protected bts endpoints. Configure TLS using the SSL transport settings for your language mapping. A Bluetooth endpoint supports the following options:

OptionDescriptionClient SemanticsServer Semantics
-a addr
Specifies the Bluetooth device address in the form xx:xx:xx:xx:xx:xx. The address must be enclosed in quotes because the colon (:) character is also a separator in the endpoint syntax. If not specified, the value of Ice.Default.Host is used instead.
An address is required for proxy endpoints. The plug-in will throw EndpointParseException if no address is specified via the -a option or Ice.Default.Host.
On Linux, the plug-in uses the address to select the Bluetooth adapter on which to listen for new connections. If no address is specified via the -a option or Ice.Default.Host, the plug-in uses the system's default adapter.On Android, the plug-in ignores this setting and always uses the system's default adapter.In addition to a Bluetooth device address, addr can also be * (e.g., bt -a * ...) to force the endpoint to use the system's default adapter without having to specify its address directly. The plug-in ignores the setting for Ice.Default.Host in this case.
-u uuid
Specifies the UUID of a service.
A UUID is required for proxy endpoints. The plug-in uses the UUID to search for a matching service at the specified device address.
A UUID is optional (but recommended) for object adapter endpoints. If this option is not specified, the plug-in generates a random UUID. The plug-in registers the service with its UUID in the local SDP registry so that clients can locate it.
-c channel
Specifies the RFCOMM channel number of the endpoint.
Not supported in proxy endpoints – the plug-in always uses the service UUID to connect to a server.
This setting is optional on Linux. The value for channel must be in the range 0-30. An available channel will be selected automatically if this setting is not specified or channel is zero.This setting is ignored on Android – the system always selects the channel.
-t timeout
Specifies the endpoint timeout in milliseconds.
The value for timeout must either be infinite to specify no timeout, or an integer greater than zero representing the timeout in milliseconds. Endpoint timeouts are deprecated. They have no effect as of Ice 3.8.
The value for timeout must either be infinite to specify no timeout, or an integer greater than zero representing the timeout in milliseconds. Endpoint timeouts are deprecated. They have no effect as of Ice 3.8.
-z
Specifies bzip2 compression.
Determines whether requests are compressed during sending.
Determines whether compression is advertised in proxies created by the adapter.
--name name
Specifies the service name.
Ignored in proxy endpoints.
Associates a human-friendly name with the service's entry in the SDP registry. If not specified, the default name is Ice Service.

iap -p protocol -n name -m manufacturer -o model number -t timeout -z iaps -p protocol -n name -m manufacturer -o model number -t

The iAP transport protocol is provided by a separate IceIAP plug-in.

The iAP transport protocol allows applications running on iOS to communicate with accessories connected to the iOS device either through Bluetooth or the lightning connector. The iAP transport protocol is a client-side transport protocol: there's no server-side support. An iAP endpoint supports the following options to allow selecting the accessory to connect to:

OptionDescriptionClient Semantics
-p protocol
Specifies the protocol implemented by the accessory.
The iAP transport protocol will only connect to accessories that advertise the specified iAP protocol. The default value for protocol is com.zeroc.ice.
-n name
Specifies the name of the accessory.
When specified, the iAP transport protocol will only connect to accessories that match the specified accessory name.
-m manufacturer
Specifies the manufacturer of the accessory.
When specified, the iAP transport protocol will only connect to accessories that match the specified accessory manufacturer.
-o model number
Specifies the model number of the accessory.
When specified, the iAP transport protocol will only connect to accessories that match the specified accessory model number.
-t timeout
Specifies the endpoint timeout in milliseconds.
The value for timeout must either be infinite to specify no timeout, or an integer greater than zero representing the timeout in milliseconds. Endpoint timeouts are deprecated. They have no effect as of Ice 3.8.
-z
Specifies bzip2 compression.
Determines whether requests are compressed during sending.

opaque -t type -e encoding -v value

Proxies can contain endpoints that are not universally understood by Ice processes. For example, a proxy can contain an endpoint for a transport that the receiver does not know.

Ice preserves such unknown endpoints when they are received over the wire. If an Ice process stringifies a proxy containing an unknown endpoint, it writes the endpoint as an opaque endpoint.

An opaque endpoint supports the following options:

OptionDescription
-t type
Specifies the endpoint type (also known as transport code) for the endpoint. TCP is 1, SSL is 2, UDP is 3, etc.
-e encoding
Specifies the encoding version used to encode the endpoint marshaled data.
-v value
Specifies the marshaled encoding of the endpoint in base-64 encoding.

Exactly one each of the -t and -v options must be present in an opaque endpoint. If -e is not specified, the default encoding used by the Ice runtime is assumed.