Content for TS 23.284 Word version: 18.0.0

1… 4… 4.2… 4.3… 5 6… 6.3… 6.3.2 6.3.3 6.3.4 6.3.5 7… 7.2.4… 7.2.4.2 7.2.4.3 7.2.4.4 7.2.4.5 7.2.4.6 7.3… 7.3.4… 7.3.4.2 7.3.4.3 7.3.4.4 8… 8.2.3 8.3… 8.3.2 8.4… 8.4.1.1.7… 8.4.1.2… 8.4.2… 8.4.2.2… 8.4.5… 8.4.5.6 8.4.5.7 8.4.5.8… 9… 13… 13.4… 13.4.3… 13.4.4… 13.5… 13.6… 13.7… 14… 16… A… A.2…

7.3.4.4 MSC server Initiated when Access Side Termination is isolated in MGW
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7.3.4.4 MSC server Initiated when Access Side Termination is isolated in MGW p. 63

Figure 7.3.4.4.1 shows the message sequence example for the MSC server initiated LCLS Re-establishment for the case when the LCLS negotiation through the Core Network enabled the MSC server to use the option to isolate access side termination from the network side termination.

In this example the oMSC server requests the oMGW to interrupt the communication on the bearer by using the Isolate Bearer Termination Procedure (i.e. to isolate access side termination T1 from the network side termination T2) after the oBSS re-established local switching.

Copy of original 3GPP image for 3GPP TS 23.284, Fig. 7.3.4.4.1: MSC server Initiated LCLS Re-establishment, access side termination isolated in MGW

Figure 7.3.4.4.1: MSC server Initiated LCLS Re-establishment, access side termination isolated in MGW
(⇒ copy of original 3GPP image)

Step 1 - 10.

When the oMSC server determines that local switching should be re-established it initiates the LCLS Re-establishment procedure specified in clause 7.3.4.2, steps 1 - 10.

Step 11.

The oMSC server send to the oMGW request to isolate the access side termination T1 from the network side termination T2.

NOTE 1:
The MSC server can also use the Change Through-Connection procedure and requests the MGW to change the through-connection of the bearer to inactive instead of using of the Isolate Bearer termination procedure, see TS 23.205.
The oMSC server sends the LCLS Status Update message with the LCLS-Status IE set to "LCLS Connected" to the succeeding node.

Step 12.

The iMSC server transfers the LCLS Status Update message to the tMSC server.

Step 13.

The tMSC server sends the LCLS Status Update message with the LCLS-Status IE set to "LCLS Connected" to the preceding node. The iMSC server does not forward the LCLS Status Update message to the oMSC server since the same LCLS Status is already received from the oMSC server.