- This topic has 68 replies, 1 voice, and was last updated 5 years, 8 months ago by Rakesh solanki.
26th October 2008 at 10:13 #54363IndranilGuest
Pls consent, how to prevent call drop due to T200 timer expiry.(network having 42% call drop error indication———- due
to T200*(N200+1)times expire-abnormal release]
BR//27th October 2008 at 08:58 #54364pixGuest
on the whole network ? 48% call drop ! that’s impossible…
T200 expiry usually refers to Abis failure, or equipment failure on one end (BTS or BSC). But if it affects the whole network, maybe you should check out your transcoder or your Ater/A interface links.
Are those interfaces “over satellite” ?
Do you have any alarm in your OMC-R ?28th October 2008 at 04:27 #54365IndranilGuest
modification is drop call reason percentage due to T200 expiry is 42% of the whole call drop.
Interfaces are not over satellite.
There are no alarm regarding it in OMCR.
I have checked those sites having drop reason due to T200 expiry,
having slips & no such event of abis failure(according to log).
Indranil.28th October 2008 at 15:25 #54366pixGuest
T200 expiry means that the LAPD frame is sent from point A to point B on Abis, but without acknowledgment from point B.
If the frame is not acknowledged, it means it has not be received. Therefore the point A will retransmit the frame up to N200 times.
At N200+1 times, the point A will stop trying –> drop.
Now, how many reasons do you for not having an ACK from point B ?
A/ either the link is broken, and point B never received the initial data
B/ point B is down (or in a faulty state) and doesn’t receive/ack the frames.
restart your processes on each end, investigate your Abis links, swap your control boards… there is not much you can do.
It’s either software pb or hardware pb.23rd April 2009 at 07:22 #54367ZiaGuest
Dear Mr. Pix,
I have the same problem as Mr. Andranil,
Data link failure due to N200 time out which cause call drop.
This data link failure is abserving in most of the area.
Do you have any more comment regarding this issue?
Zia28th April 2009 at 04:31 #54368InnovaGuest
Indranil said having slips,I guess there were clocking issues so a transmission configuration problem.20th May 2009 at 06:30 #54369HAMEDGuest
what t200 timer?
maximum of call drops in my network cause of t200.
help me for solusion.
thanks20th May 2009 at 06:34 #54370HAMEDGuest
how to prevent call drop due to T200 timer expiry20th May 2009 at 07:03 #54371PixGuest
As said earlier (just read older posts in this thread), it’s probably because of :
1/ Abis link failure
2/ Clock/Transmission BTS board failure
3/ Transmission BSC board failure
Pick your choice.28th May 2009 at 11:46 #54372Deepak KGuest
Can any one tell me that how can we know the number of drop call due to T200 exipry in nokia system ???2nd June 2009 at 04:59 #54373ShikhaGuest
Plz let me know about the LAPD Call drop.Can you explain,what is LAPD.2nd June 2009 at 05:28 #54374PixGuest
LapD is the signaling ‘link’ on the Abis.
Basically, it just means that there was a failure on the Abis, causing drops on the Air interface (as soon as the Abis is down, all calls handled by this abis are dropped)9th June 2009 at 18:52 #54375silviaGuest
T200 Timer.9th June 2009 at 19:06 #54376silviaGuest
what is a T200?10th June 2009 at 05:08 #54377JohnGuest
Plz let me know about the LAPD Call drop.Can you explain,what is LAPD.