Session Directory

Session Directory

Session Directory (SDR) is an MBONE scheduling system used to announce and schedule multimedia conferences. SDR uses the Session Directory Announcement Protocol (SDAP) that will periodically multicast a session announcement packet describing a particular session. SDAP announcement packets can be received by a multicast receiver by joining the well-known group 224.2.127.254. A user can then select to receive traffic for a multicast group using the SDR tool (see Figure 9-4).

Figure 9-4: Sample output for the Session Directory

To enable the reception of Session Directory Protocol announcements on an interface, use the interface command

ip sdr listen

This command enables the router to accept SDAP packets on the interface, and the router joins the multicast group 224.2.127.254. SDR entries are cached on the router and the time that an SDR remains in the cache is configured using the global configuration command:

ip sdr cache-timeout minutes

minutes

The amount of time an SDR cache entry stays active in the cache. A value of 0 indicates the entry will never time-out. The default value is 24 hours.

The remaining commands pertaining to SDR are listed below.

debug ip sdr

The above command enables logging of received SDR announcements.

show ip sdr [group | “session-name” | detail]

no parameters given

A sorted list of cached sessions names are displayed.

group

Detailed information is displayed for the multicast group.

detail

Displays sessions in detailed format.

This command displays the entries in the SDR cache if the router is configured to listen to SDR announcements.

clear ip sdr [group-address | “session-name”]

no parametersClears the SDR cache.

Clears all sessions associated with the given group-address.

Clears the cache entry for the given session name.