The Link filter entry (SERVICE_LINK_FILTER, SERVICE_LINK_ID) conveys information about the upstream sources that provide data to a service.
This information is represented as a Map, where each MapEntry represents one upstream source. The map entry key is the name associated with the communication link, and is of type ASCII. This name is scoped globally, and if multiple sources have the same name, they are assumed to be identical and the aggregating system will balance requests among them.
A typical consumer application can treat this entry as mainly informational. The consumer should use the State category to make programmatic decisions about service availability and status.
Any default behavior is explained in the Element’s description.
Table 30: Source Directory Link FilterEntry Map Contents
ELEMENT NAME
TYPE
RANGE/EXAMPLE
DESCRIPTION
Type
UInt
1 | 2
Indicates whether the upstream source is interactive or broadcast. This does not describe whether the service itself is interactive or broadcast.
• 1: The upstream source is interactive (this is the default).
• 2: The upstream source is a broadcast source.
LinkState
UInt
0 | 1
Required. Indicates whether the upstream source is up or down
• 0: The upstream source is down.
• 1: The upstream source is up.
LinkCode
UInt
0 - 3
Provides additional information about the upstream source.
• 0: None (this is the default)
• 1: Ok
• 2: RecoveryStarted
• 3: RecoveryCompleted
Text
ASCII
N/A
Explains the LinkState and LinkCode. Text defaults to “”.