- This topic has 28 replies, 1 voice, and was last updated 4 years ago by Neel.
7th July 2009 at 06:02 #57200PanGuest
Yes, the mobile subscription record is deleted from VLR. It is impossible to establish any MO call without previous Location Update, but subscriber usually doesn’t notice this.7th July 2009 at 09:06 #57201VikiGuest
But if the mobile subscription record is deleted from VLR, what is the reason to freeze TMSI there?
In this case we will have a list of frozen (not available for usage for others) TMSIs with no subscribers registered.7th July 2009 at 09:57 #57202PixGuest
If the MS is “IMSI detached” (= it is purged from VLR), it should still be able to establish a MO call, no? It just can’t receive a call, because it will not be paged.
What do you think ?7th July 2009 at 12:20 #57203PanGuest
Implicit Imsi Detach is not equal to VLR purge.
1)Implicit IMSI Detach = subscriber is marked as detached in VLR; subscriber’s data isn’t deleted from VLR; there is no contact between VLR and HLR; TMSI isn’t froze because subscriber’s data are staying in VLR.
2)VLR purge = subscriber’s data is deleted from VLR and VLR sends VLR purge message in HLR. TMSI may be frozen according procedure. There is no interaction attempt between HLR and VLR when MT call arises and subscriber is marked as purged in HLR.
Pix, when subscriber is marked as “implicit detached” in VLR, there is possibility to establish MO call without VLR-HLR interaction (I think it is VLR implementation dependent to do this with or without Location Updating).
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http://www.erlang.com – cool!!!!29th July 2009 at 06:10 #57205PixGuest
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One erlang… errr… not that cool 🙂15th September 2009 at 06:15 #57206JEMO FROM UGGuest
YOU GUYS A SHARING SOME REALLY GOOD STUFF. NOW WHY CANT SOME NUMBERS BE ABLE TO CALL SHORT NUMBERS SAY CALLING 999 OR112 OR 123 IF THESE ARE SAY HELPLINES30th September 2010 at 08:30 #57207bernardGuest
can you give me your quick recommendation for purge timer or anything to improve SMSMT. We have set IDT to 2hrs to improve paging. Im currently thinking to modify MS purge timer and/or SMSC retry interval. Major cause for my SMSMT is “subscriber absent” and SMSC still attempts even when MS is detached(power off).
my current setting is;
purge timer = 7days
SMSC retries at an interval 5 mins, 5 mins, 10min… and after 8hrs before the SM be deleted.
Thanks very much.23rd March 2011 at 12:28 #57208selvakumarGuest
Say example for out of coverage and not reachable(IMSI Detach)25th May 2012 at 16:52 #57209Leo DennisGuest
In case mobile is marked as dettached in the VLR and subscriber data are added, deleted or changed in the HLR, the VLR will be updated via insert data MAP msg ?27th May 2014 at 18:32 #57210harisGuest
I would like to know the ISUP cause code for the case MS Purged from VLR.
Is it correct the cause code is should be ‘Subscriber Absent’ or any others such as ‘Normal Unspecified’?22nd November 2016 at 19:55 #57211AnshulGuest
After successful purge in VLR , what is timer in HLR to store previous VLR address in it . I mean till what time its visible in HLR.26th November 2016 at 15:31 #57212Wallis DudhnathGuest
The ISUP cause codes are based on the earlier ISDN standards.
Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN User Part. Look at the following ISDN specifications: Q.931 and Q.850.
This cause value is used when a mobile station has logged off, radio contact is not obtained with a
mobile station or if a personal telecommunication user is temporarily not addressable at any usernetwork
interface.23rd February 2017 at 09:40 #57213NeelGuest
Why VLR purging is required after STP fluctuations in ICR network