NEC Univerge sv8500 Manual page 3053

The currently applied interval flashes.
Note:
STEP 4: After Retransmit Interval is set, press OK key and go back to the Extra Function Menu.
STEP 5: Press Exit key on the Extra Function Menu to return to the SIP Settings Menu.
STEP 6: Press Exit key on the SIP Settings Menu and go back to the Main Menu.
STEP 7: Press Save key on the Main Menu to save the assigned data.
4.2.7.2 Keeping Call
On the Keeping Call parameter, set whether call connection is kept up even if DtermIP(SIP) detects that
communication failure occurs between the system and DtermIP(SIP).
This parameter is available for DtermIP (SIP) with Firmware Version 4.1.x.x or later.
Note:
STEP 1: Select "7. Extra Function" by pressing "7" key on the SIP Settings Menu.
STEP 2: Extra Function Menu appears. Select "2. Keeping Call" by pressing "2" key on the Extra Function
Menu.
1.Standard
2.6 seconds
Cancel
SIP Settings Menu
21.User
2.Server Address & URI
3.Access Mode
4.SIP Server Port
5.Area ID
6.Encryption
7.Extra Function
Up Down
Exit
Extra Function Menu
271.Retransmit Interval
2.Keeping Call
3.Howler Tone
4.Language Pattern
Exit
Up Down
VOL.3-566
CHAPTER 4 CONFIGURATION SETUP
OK