Service Request

SrvRqst

1

Issued by a UA to find services or by a UA or SA server during active DA discovery.

Service Reply

SrvRply

2

The DA or SA response to a service request.

Service Registration

SrvReg

3

Enables SAs to register new advertisements, to update existing advertisements with new and changed attributes, and to refresh URL lifetimes.

Service Deregistration

SrvDereg

4

Used by the SA to deregister its advertisements when the service they represent is no longer available.

Acknowledgment

SrvAck

5

The DA response to an SA's service request or service deregistration message.

Attribute Request

AttrRqst

6

Made either by URL or by service type to request a list of attributes.

Attribute Reply

AttrRply

7

Used to return the list of attributes.

DA Advertisement

DAAdvert

8

The DA response to multicast service requests.

Service Type Request

SrvTypeRqst

9

Used to inquire about registered service types that have a particular naming authority and are in a particular set of scopes.

Service Type Reply

SrvTypeRply

10

The message that is returned in response to the service type request.

SA Advertisement

SAAdvert

11

UAs employ the SAAdvert to discover SAs and their scopes in networks where no DAs are deployed.