Hi,

Josh is right.

2.5 msec frame also was created to provide much lower latency for fixed ratios: 
75/25, 50/50, 30/70.

The headline throughput will be a little less, because there is more frame 
overhead since double the amount of packets / frames, but overall latency is 
decreased which can help TCP and also increase TCP throughput.  Throughput for 
2.5 versus 5 msec should be compared for each case.

Dan Sullivan
ePMP Software Manager

From: Af [mailto:[email protected]] On Behalf Of Josh Luthman
Sent: Saturday, December 05, 2015 12:57 PM
To: [email protected]
Subject: Re: [AFMUG] ePMP 2.5ms frame

Absolutely lower latency.  Should be identical to pmp100 I think?  Definitely a 
lot better than the 5ms.


Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373

On Sat, Dec 5, 2015 at 1:55 PM, Adam Moffett 
<[email protected]<mailto:[email protected]>> wrote:
Yeah, but I haven't had to colo it with a PMP100 so at the time I glossed over 
it.

I was wondering if I was missing out on lower latency.....sounds like that's a 
yes.

On 12/5/2015 10:22 AM, Gino Villarini wrote:
wasnt 2.5 frames announced some time ago?

On Fri, Dec 4, 2015 at 9:15 PM, Josh Luthman 
<[email protected]<mailto:[email protected]>> wrote:

Like 80% sure I'm right but ya latency is the most important.

Josh Luthman
Office: 937-552-2340<tel:937-552-2340>
Direct: 937-552-2343<tel:937-552-2343>
1100 Wayne St
Suite 1337
Troy, OH 45373
On Dec 4, 2015 7:47 PM, "Mathew Howard" 
<[email protected]<mailto:[email protected]>> wrote:
Isn't throughput supposed to be slightly worse with 2.5ms, or am I remembering 
that wrong? There is definitely a big improvement in latency.
Either way, I don't think the difference in throughput is enough to care about, 
I'd rather have the lower latency.

On Fri, Dec 4, 2015 at 1:59 PM, Josh Luthman 
<[email protected]<mailto:[email protected]>> wrote:
A bit more throughput.  Not worth changing from 5ms to 2.5ms if all you're 
after is throughput.  Any new APs I do 2.5ms instead of 5ms since there's no 
reason to do it "the old way".  You do get better latency - 7.5ms improvement.


Josh Luthman
Office: 937-552-2340<tel:937-552-2340>
Direct: 937-552-2343<tel:937-552-2343>
1100 Wayne St
Suite 1337
Troy, OH 45373

On Fri, Dec 4, 2015 at 2:56 PM, Adam Moffett 
<[email protected]<mailto:[email protected]>> wrote:
It's a big day for ePMP threads.

If I recall correctly, the 2.5ms frame size was introduced to aid in 
collocation with the PMP100.  Is there any performance impact?  My first 
thought was that a shorter frame would give me lower latency, but it's probably 
not that simple.






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