UTStarcom iSpirit 3026 Manual page 155

4. Message Format of IGMPV2
Figure 14-4 IGMPV2 Message Format
Type (Type):
0x11 = Membership Query inquire about sub-type with two members relationship:
General Query, used for knowing of that if there are members in bcommand Internet.
Group-Specific Query, used for knowing of that if there are members in specific group in
bcommand Internet
0x16 = Edition 2 Member Relation Report
0x17 =Out Group
0x12 =Edition 1 Member Report, ensure it is compatible with IGMP v1
MRT, Max Response Time:
The Max. response time field is only valid in membership query. It is specified the Max. response
time to send a response packet (Unit: 1/10 second). In all other messages, sender set it into, but
receiver ignores the field.
Checksum:
It is the message length of IGMP (the whole effect load of IP packet) 16-digit inspection. The
field is set into 0, please together with this field packet to make account about the field packet. If
you want to send out packet, the Checksum must be accounted and inserted into the field. The
Checksum must be inspected before processing this packet.
GDA:
In membership query message, group address field when send General Query should be set
into 0. Group address should be set when send one Group-Specific Query. In the message of
Member Report and Out Group, group address field should be set into the address of
Report-Desire or Out-Desire.