2.2.2.2 Multicast Session Initiation Reply Packet

The server sends this packet in response to Multicast Session Initiation Request Packet when the requested content has been set up for delivery using multicast session. The reply packet MUST be sent using the UDP port specified in section 1.9 by the server. If an error occurs that prevents the server from setting up the content for delivery using multicast session, then the server sends the reply packet as specified in section 2.2.2.3.

The format for this packet is specified in section 2.2.2. The packet MUST include the options specified below.

Option Id	Description
WDSMCSE_OPT_MULTICAST_ADDR 0x0503	Specifies the multicast IP address for the multicast session. The value MUST specify a 4-byte address for an IPv4 multicast address, and a 16-byte address for an IPv6 multicast address.
WDSMCSE_OPT_SERVER_ADDR 0x0504	Specifies the IP address of the network interface card being used by the multicast session. The value MUST specify a 4-byte address for an IPv4 address and a 16-byte address for an IPv6 address.
WDSMCSE_OPT_MULTICAST_PORT 0x0205	MUST be set to the UDP port being used by the multicast session to transmit packets to the multicast address specified by the WDSMCSE_OPT_MULTICAST_ADDR field. The value MUST be a 2-byte unsigned numeric value.
WDSMCSE_OPT_SERVER_PORT 0x0206	MUST be set to the same value as the WDSMCSE_OPT_MULTICAST_PORT field.
WDSMCSE_OPT_CONTENT_SIZE 0x0407	Specifies the total size, in bytes, for the content. The value is a 64-bit unsigned numeric value.
WDSMCSE_OPT_BLOCK_SIZE 0x0309	Content is divided into equal blocks of data by the WDS Multicast Transport Protocol. This variable specifies the size of each block in bytes. The last block of data for content MAY be smaller in size because the size of content MAY NOT be fully divisible by the WDSMCSE_OPT_BLOCK_SIZE field. The value is a 32-bit unsigned numeric value.
WDSMCSE_OPT_TOTAL_BLOCKS 0x0408	MUST be set to the total number of blocks the content has been divided into. The value is a 64-bit unsigned numeric value.
WDSMCSE_OPT_SESSION_ID 0x030A	MUST be set to a numeric value that uniquely identifies the multicast session on the server. The value is a 32-bit unsigned numeric value.