# nw_connection_group_t An object you use to communicate with a group of endpoints, such as an IP multicast group on a local network. ``` typealias nw_connection_group_t = any OS_nw_connection_group ``` ## Topics ### Establishing Group Connectivity [`nw_connection_group_create(_:_:)`](/documentation/Network/nw_connection_group_create(_:_:)) Initializes a new connection group with a group identifier. [`nw_group_descriptor_create_multicast(_:)`](/documentation/Network/nw_group_descriptor_create_multicast(_:)) Creates group descriptor you use to join an IP multicast group on a local network. [`nw_group_descriptor_t`](/documentation/Network/nw_group_descriptor_t) A type that defines a group of endpoints with which you can communicate, such as a multicast group. [`nw_group_descriptor_add_endpoint(_:_:)`](/documentation/Network/nw_group_descriptor_add_endpoint(_:_:)) Adds a multicast address endpoint you specify to define an extra IP multicast group to join. [`nw_group_descriptor_enumerate_endpoints(_:_:)`](/documentation/Network/nw_group_descriptor_enumerate_endpoints(_:_:)) Sets a handler to list all endpoints added to the group descriptor. [`nw_group_descriptor_enumerate_endpoints_block_t`](/documentation/Network/nw_group_descriptor_enumerate_endpoints_block_t) A handler that lists all endpoints added to the group descriptor. [`nw_connection_group_set_queue(_:_:)`](/documentation/Network/nw_connection_group_set_queue(_:_:)) Sets the queue on which you handle connection group events. [`nw_connection_group_start(_:)`](/documentation/Network/nw_connection_group_start(_:)) Joins the group and registers to receive messages. ### Sending and Receiving Group Messages [`nw_connection_group_set_receive_handler(_:_:_:_:)`](/documentation/Network/nw_connection_group_set_receive_handler(_:_:_:_:)) Sets a handler that receives inbound messages from members of the group. [`nw_connection_group_receive_handler_t`](/documentation/Network/nw_connection_group_receive_handler_t) A handler that receives inbound messages from members of the group. [`nw_connection_group_copy_remote_endpoint_for_message(_:_:)`](/documentation/Network/nw_connection_group_copy_remote_endpoint_for_message(_:_:)) Accesses the endpoint that originates the message you receive. [`nw_connection_group_copy_local_endpoint_for_message(_:_:)`](/documentation/Network/nw_connection_group_copy_local_endpoint_for_message(_:_:)) Accesses the local address and port you use to receive the message. [`nw_connection_group_copy_path_for_message(_:_:)`](/documentation/Network/nw_connection_group_copy_path_for_message(_:_:)) Accesses the network path on which you receive the message. [`nw_connection_group_reply(_:_:_:_:)`](/documentation/Network/nw_connection_group_reply(_:_:_:_:)) Sends a reply to the specific endpoint that originates a group message you receive. [`nw_connection_group_extract_connection_for_message(_:_:)`](/documentation/Network/nw_connection_group_extract_connection_for_message(_:_:)) Converts a message you receive from an endpoint into a connection object that you use for long-term communication with that endpoint. [`nw_connection_group_send_message(_:_:_:_:_:)`](/documentation/Network/nw_connection_group_send_message(_:_:_:_:_:)) Sends data to the entire group, or to a specific member of the group. [`nw_connection_group_send_completion_t`](/documentation/Network/nw_connection_group_send_completion_t) A completion to notify you when data has been processed and sent. ### Managing Groups [`nw_connection_group_set_state_changed_handler(_:_:)`](/documentation/Network/nw_connection_group_set_state_changed_handler(_:_:)) Sets a handler that receives connection group state updates. [`nw_connection_group_state_changed_handler_t`](/documentation/Network/nw_connection_group_state_changed_handler_t) A handler that receives connection group state updates. [`nw_connection_group_state_t`](/documentation/Network/nw_connection_group_state_t) States that indicate whether you can use a connection group to send and receive messages. [`nw_connection_group_cancel(_:)`](/documentation/Network/nw_connection_group_cancel(_:)) Cancels the connection group object and leaves the network group. ### Inspecting Groups [`nw_connection_group_copy_descriptor(_:)`](/documentation/Network/nw_connection_group_copy_descriptor(_:)) Accesses the descriptor of the group you use to initialize the connection group. [`nw_connection_group_copy_parameters(_:)`](/documentation/Network/nw_connection_group_copy_parameters(_:)) Accesses the parameters with which you initialize the connection group. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)