Ping times on 3G and EDGE

I'm crunching the numbers for a large corporate who will need to connect one of their control center to their private APN. And it became clear to me that the only obstacle to using MTN (as opposed to a leased line) would be the longer RTT times.

So my question is : How can we get the lowest possible RTT times to the private APN ?

Can anybody with an active internet GPRS or EDGE link do a few pings and post some results ?

The RTT times will continue to come down with each software upgrade. Our first GPRS test unit used to generate around 3000 ms whereas now the nominal EDGE value is around 400 ms and 3G is approx half of that.

We recently drove through a residential suburb for our own in-house testing and did 100 back-back pings of 32 bytes and the result was min 407 ms, max 890 ms and average 521 ms. 3G did a lot better but with a similar max value.

We clipped about 70 ms off GPRS (across the board) last year and EDGE still has a way to go. Nevertheless we only want to sell corporates solutions that really do work. Part of the Corporate Mobility solution includes banks of modems which constantly test such parameters. My mailbox overflowed when I took yesterday off sick but if you private mail me (say late Friday) I'll see if we can access some of these private apn stats.

nicroets said:

I'm crunching the numbers for a large corporate who will need to connect one of their control center to their private APN. And it became clear to me that the only obstacle to using MTN (as opposed to a leased line) would be the longer RTT times.

So my question is : How can we get the lowest possible RTT times to the private APN ?

Can anybody with an active internet GPRS or EDGE link do a few pings and post some results ?

Click to expand...

Nic - what sort of applications will they be using on the private APN? One thing to remember - the APN ping times are generated from inside your network - so responses to the net will depend on the amount of bandwidth the corp has available, and if there is any QoS on ICMP traffic. When you install a private APN, both Voda and MTN insist that you configure QoS on the link (via MPLS or Qos Devices on a direct circuit).
PM me if you want more details on the RTT times - I have some info on it, but I first need to explain the context to you before posting...

Look it'll be a year or more before the system goes operational, so we're just researching.

The application is to monitor and contol devices (switching things on and off) throughout the country from 1 or 2 locations (Jhb CBD and perhaps Cpt CBD). The total payload seems to be in the 1GB/month range. For security reasons (or perhaps just paranoia) a private APN is the only option on the table.

Our initial thoughts where that a leased line to the APN is necessary. But it can also be done with a GPRS/EDGE/3G modem in the control center : The model shows that, even if the control center looses contact for a minute or two every few hours (which I'm sure it doesn't), the delays will not cost the company more than the leased line. It's only extended outages (30 minutes) that will cause real havoc.

When I posted the question I was more concerned about effect of the extra delay of going wireless a second time (modem -> MTN -> APN -> MTN -> modem). But now I realize RTT delays are *anticipated* whereas outages are not. So adding 500ms will not be a problem.

Excellent. We've done quite a few telemetry applications so would be great to chat in more detail closer to the time. A year is a long time in this business and we'll have a few relevant improvements to discuss by then.

Long Ping times

MTNBroadband said:

Excellent. We've done quite a few telemetry applications so would be great to chat in more detail closer to the time. A year is a long time in this business and we'll have a few relevant improvements to discuss by then.

Click to expand...

Hi,

I am also experimenting with this and am getting ping times of about 1.7 seconds. Any suggestions?

good luck getting a reply from MTN on this forum.