Established Member
Apogee
Posts: 1,005
Registered: ‎09-29-2009
Posts: 1005
Kudos: 64
Solutions: 1
Registered: 09-29-2009

airMax - aggregation - priority

Anybody know how the airMax priority affects aggregation settings?

It seems to me that they should be adjusted based on priority since the time slice to xmit frames is different based on priority and active stations. Does airMax adjust agg settings automagically when needed? Does fragmentation occur if the aggregate frame is larger than the available airMax slot to xmit it?

Anybody have the scoop on this?
Rural Crossing
Internet & Community Networks
Northeast Indiana; Northwest Ohio; Lower Michigan
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

Anybody know how the airMax priority affects aggregation settings?

It seems to me that they should be adjusted based on priority since the time slice to xmit frames is different based on priority and active stations. Does airMax adjust agg settings automagically when needed? Does fragmentation occur if the aggregate frame is larger than the available airMax slot to xmit it?

Anybody have the scoop on this?


Good question :manhappy:
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
Established Member
Apogee
Posts: 1,005
Registered: ‎09-29-2009
Posts: 1005
Kudos: 64
Solutions: 1
Registered: 09-29-2009

Re: airMax - aggregation - priority

Nobody knows? Not even the ubi engineers?

I did a few tests last night and it looks like aggregation may be linked to the metrics|performence issues I and others have been reporting...so far. I won't be able to tell for sure until until ubi explains the relationship with am.
Rural Crossing
Internet & Community Networks
Northeast Indiana; Northwest Ohio; Lower Michigan
Established Member
Apogee
Posts: 1,005
Registered: ‎09-29-2009
Posts: 1005
Kudos: 64
Solutions: 1
Registered: 09-29-2009

Re: airMax - aggregation - priority

I've been fooling with aggregation settings all morning and was able to increase bandwidth across my entire network...up to double the previous bandwidth per device by NOT USING THE DEFAULT 32/50000!

The answer to the op would be important information for Ubiquiti to share with us!!!
Rural Crossing
Internet & Community Networks
Northeast Indiana; Northwest Ohio; Lower Michigan
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

I've been fooling with aggregation settings all morning and was able to increase bandwidth across my entire network...up to double the previous bandwidth per device by NOT USING THE DEFAULT 32/50000!
The answer to the op would be important information for Ubiquiti to share with us!!!

What settings are you using? It would make more sense that the size be a multiple of the wireless mtu and not some flat number.
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
Established Member
rhauf
Posts: 1,243
Registered: ‎09-17-2010
Posts: 1243
Kudos: 255
Solutions: 6
Registered: 09-17-2010

Re: airMax - aggregation - priority

Oh things are getting interesting? its like an investigation of airmax magic sauce and ways to make it tastier.
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

Something else to think about is the amount of buffer space spread across the time slots, and the number of CPEs.
Aggregation would be less efficient as you spread timeslots out among more CPEs.
Also, there is a possible problem as you queue up frames to spread out among those CPEs that you run out of buffer space.
In a pure PtP scenario though, you would (in theory) max out the number of frames (32) and the size of those frames as a multiple of the wireless MTU (2024). (64768 byte packets).
I just tested this and got a small performance bump over the flat 50000 byte frames, and slightly lower latency. (This is a non-airmax scenario)
Wonder why that isn't the default?
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
Ubiquiti Employee
UBNT-Matt
Posts: 5,941
Registered: ‎11-27-2007
Posts: 5941
Kudos: 2581
Solutions: 69
Contributions: 39
Registered: 11-27-2007

Re: airMax - aggregation - priority

I've been fooling with aggregation settings all morning and was able to increase bandwidth across my entire network...up to double the previous bandwidth per device by NOT USING THE DEFAULT 32/50000!


What changes did you make? If you have poor links, using aggregation may perform worse (if a smaller packet is dropped it's okay, but if larger packets are dropped, more data is lost -- nothing magic here).

What did you find? Lowering aggregation gave you better performance?

-Matt
Ubiquiti Employee
UBNT-Edmundas
Posts: 3,879
Registered: ‎05-13-2009
Posts: 3879
Kudos: 563
Solutions: 46
Registered: 05-13-2009

Re: airMax - aggregation - priority

Anybody know how the airMax priority affects aggregation settings?

It seems to me that they should be adjusted based on priority since the time slice to xmit frames is different based on priority and active stations. Does airMax adjust agg settings automagically when needed? Does fragmentation occur if the aggregate frame is larger than the available airMax slot to xmit it?

Anybody have the scoop on this?


Aggregate size is adjusted depending on link conditions and what is specified in UI is the maximum. Lower priority CPEs get less slots but aggregation is not dependent on priority but on link conditions.

-Edmundas
Member
aragon
Posts: 152
Registered: ‎03-03-2010
Posts: 152
Kudos: 16
Registered: 03-03-2010

Re: airMax - aggregation - priority

Aggregate size is adjusted depending on link conditions and what is specified in UI is the maximum. Lower priority CPEs get less slots but aggregation is not dependent on priority but on link conditions.

Is aggregation reduced/disabled for packets marked for realtime/voice priority with DSCP?
Ubiquiti Employee
UBNT-Edmundas
Posts: 3,879
Registered: ‎05-13-2009
Posts: 3879
Kudos: 563
Solutions: 46
Registered: 05-13-2009

Re: airMax - aggregation - priority

Is aggregation reduced/disabled for packets marked for realtime/voice priority with DSCP?


Yes. These packets will be less aggregated.

-Edmundas
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

aragon: Are you aware of the packet markings that AirMax pays attention to btw?

wiki.ubnt.com/Main_Page/QoS_DSCP/TOS_Mappings
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
Established Member
rhauf
Posts: 1,243
Registered: ‎09-17-2010
Posts: 1243
Kudos: 255
Solutions: 6
Registered: 09-17-2010

Re: airMax - aggregation - priority

oh man, now i want to assign lowest QoS priority to video (netflix) traffic.. how can i do that?
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

oh man, now i want to assign lowest QoS priority to video (netflix) traffic.. how can i do that?


LOL really? That's not a good solution. You want to QoS it higher than a lot of traffic, but LIMIT the maximum bitrate, so the customer is forced to change their streaming bitrate.

That way they have buffer-free streaming that doesn't harm your infrastructure(unless all of your users are watching netflix!)
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
Established Member
rhauf
Posts: 1,243
Registered: ‎09-17-2010
Posts: 1243
Kudos: 255
Solutions: 6
Registered: 09-17-2010

Re: airMax - aggregation - priority

currently, nobody is having any problems streaming netflix or other video sources.
yes your solution is even better. now how to go about doing that hmm.
SuperUser
Bean_Planter
Posts: 5,501
Registered: ‎08-09-2011
Posts: 5501
Kudos: 2406
Solutions: 174
Contributions: 10
Registered: 08-09-2011

Re: airMax - aggregation - priority

Netflix user education:
technologizer.com/2011/06/23/got-bandwidth-caps-netflix-has-you-covered/
Do it on the router (like the Mikrotik):
wiki.mikrotik.com/wiki/Limiting_a_user_to_a_given_amount_of_traffic_II
Subscribe to a very inexpensive service that automatically does the router thing for you:
www.dynamicbandwidthshaper.com/
'hope this is helpful in some way.
Cheers,
Gene
NEW FORUM MEMBERS:
Seek knowledge. Press the [Knowledge Base] link at the top.
SuperUser
Josh_SPITwSPOTS
Posts: 18,446
Registered: ‎11-20-2011
Posts: 18446
Kudos: 5800
Solutions: 143
Registered: 11-20-2011

Re: airMax - aggregation - priority

Gene you are such a stud :manwink:
Josh Reynolds :: Chief Information Officer :: www.spitwspots.com
Ubiquiti Certified Trainer :: UBWA, UEWA
SuperUser
Bean_Planter
Posts: 5,501
Registered: ‎08-09-2011
Posts: 5501
Kudos: 2406
Solutions: 174
Contributions: 10
Registered: 08-09-2011

Re: airMax - aggregation - priority

NEW FORUM MEMBERS:
Seek knowledge. Press the [Knowledge Base] link at the top.
Established Member
Apogee
Posts: 1,005
Registered: ‎09-29-2009
Posts: 1005
Kudos: 64
Solutions: 1
Registered: 09-29-2009

Re: airMax - aggregation - priority

What changes did you make? If you have poor links, using aggregation may perform worse (if a smaller packet is dropped it's okay, but if larger packets are dropped, more data is lost -- nothing magic here).

What did you find? Lowering aggregation gave you better performance?

-Matt


It depended on the link. That 900mhz bh I *****ed about for a year doubled in throughput when I increased bytes to 65000 on the AP side and lowered bytes to 3839 on the sta. I kept frames @ 32. The reason I lowered the sta side is because I sell asym access and most of the outbound from subs should be acks.

I lowered the bytes to 32000 on APs with subs in nLOS or NLOS areas and set all subs to 3839.

Still fooling with combinations...spent the last 2 days doing service calls because of dish spins. The pic shows how windy it gets around here.
Rural Crossing
Internet & Community Networks
Northeast Indiana; Northwest Ohio; Lower Michigan
20120425_091316.jpg
Established Member
Apogee
Posts: 1,005
Registered: ‎09-29-2009
Posts: 1005
Kudos: 64
Solutions: 1
Registered: 09-29-2009

Re: airMax - aggregation - priority

Aggregate size is adjusted depending on link conditions and what is specified in UI is the maximum. Lower priority CPEs get less slots but aggregation is not dependent on priority but on link conditions.

-Edmundas


This does not jive with my results so far.

Does am pri affect link conditions?
Rural Crossing
Internet & Community Networks
Northeast Indiana; Northwest Ohio; Lower Michigan