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23rd October 2012 at 09:52 #68661DjoGuest
In our network we are using ZTE PS Core. The Attach License is 12400 and PDP license is 37200. Actual usage is 800 PDP context per day. The install BW is 50 Mbps and daily usage is between 10 Mbps to 20 Mbps. The issue we are facing is the GPRS/EDGE is very slow with arround 50 paquets lost when i’m doing ping from USB dongle. Is someone can help me to troubleshoot the issue ?
Djo23rd October 2012 at 18:20 #68662pixGuest
a slow PS throughput can be caused by many issues, and most of them are NOT due to core network capacity.
First of all, you need to ensure that you have enough capacity on:
Air (radio) interface : PDCH capacity
Abis interface : packet abis ts capacity
Ater PS interface : packet ater capacity
once you are cleared on capacity, you can have a look at radio quality (coding scheme, retransmission)
50 packets lost, over how many packets ?
how do you count lost packets -> based on EGPRS ACK/NACK messages ? In such case, keep in mind that EGPRS is based on a typical threshold of 10% of retransmissions. Packets cannot be “lost” (afaik), they are only being retransmitted, except in case of real time.
pix24th October 2012 at 11:15 #68663DjoGuest
thank you for your quick response. I’m goin to check if we have enough PDCH, Abis TS and Ater capacity.
For the packets lost, someone did a ping with 100 packets and we have lost 50% of them.
Djo24th October 2012 at 17:58 #68664pixGuest
haaaa. it’s “pinging” ! the worst scenario 🙂
any specific pattern of lost packets ? exactly one every other packet ? or the first 50 packets are lost, and the 50 are correctly transmitted ?
how much delay between two sending of packets (seconds) ?
how big are your packets (bytes) ?
are you pinging from your MS to the network, or from the network to your MS ?
with ping, the thing is that there are actually two transmission : 1 in the transmission, and 1 in the reception (the ping ack). Each is using it’s own TBF.
If the delay between 2 pings is big, i would recommend you increase the Delayed DL TBF duration and Delayed (or Extended) UL TBF duration so that it matches (or exceeds) the delay between two pings.
You can also copy/paste the printout from the cmd prompt 🙂