Wireless Access

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Access network design for branch, remote, outdoor and campus locations with Aruba access points, and mobility controllers.
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VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

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  • 1.  VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Aug 31, 2015 01:53 PM

    Hi everyone, 


    We use iPhones 5-6 for multiples applications(email,picture,video,browsing,intranet...) in our industry, the most crucial of them is the VOIP on our SIP system (old nec SV8100, we will change this system soon but it's working fine for now). My SIP client app is "Bria for iPhone", that's the best i found.


    I got some support from aruba and from an external company to set this up and tweak it for iPhone only (802.11k 802.11r , client match ...). Right now i'm stuck because the power antenna on the iPhone is not strong enough compared to the wifi antenna, i know that iPhones are not made for entreprise VOIP on wifi but i want to see how i can help. 


    The main reason why i'm posting this here is because i don't have any tools. Not because i can't buy them, but because there's no professional apps on IOS to really analyse AP signals and roaming from a client perspective, there's nothing that can simulate iPhone/IOS roaming profile/power and finally SNR seems based on the device (iPhone) reception power and not the AP reception power.


    This is resulting in a big problem, my users on iPhone can hear people well, but people have a lot of trouble hearing users on iPhone.



    My solutions are ;


    Lower APs power : doing it will reduce AP transmission zone so it will force the client to roam faster to another AP. ( i don't have any testing environement and i'm afraid that this will degrade conversation both way)


    Lower heigh of my APs : our roof is 30+ feet , i was thinking about lower my APs down to around 20feet from the ground, this will reduce transmission zone of my AP and transmission power from iPhone will be better.


    Adding more APs : this will reduce zone , add more roaming ... but cost a lot more


    I know that my iPhone are client matching a lot , but is it working everytime , should they roam even more? iPhone are stuck with a threshold of -70db, i would like change this but i don't find anything talking about this even with jailbreak.  



  • 2.  RE: VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Aug 31, 2015 11:04 PM


    I think the only real way that you are going to be able to get to the bottom of it and work out exactly what is required is to perform a survey.


    While I am not 100% sure of IOS offerings I do know that there is Ekahau Site Survey (http://www.ekahau.com/wifidesign/ekahau-mobile-survey) and Airmagnet Air Mapper (http://www.flukenetworks.com/enterprise-network/wireless-network/AirMagnet-AirMapper) that both have android versions that can be used to survey and determine that a phone/tablet is seeing in the wireless space.


    I have used them both and have found them both to be very good alongside with their full blown survey equipment. While not 100 percent the same as an IOS in terms of wireless properties they should be close enough for you to be able to work out if just changing the height of the access points will have an impact or if you need to add additional access points as well if there are coverage holes.


    Without a survey you are just going to be doing trial and error which can be time consuming and may still not get you then end results you are looking for.


    I hope that helps.

  • 3.  RE: VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Sep 01, 2015 07:04 AM

    What access point are you using and what transmit power?  Did you take a look at the whitepaper about VOIP on handheld clients here?  http://www.arubanetworks.com/pdf/WP_SmartphoneVoIP.pdf   It is old, but gives you an idea about what happens with VOIP clients.   Hopefully you have enabled and configured WMM on the Bria client already.  


  • 4.  RE: VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Sep 01, 2015 09:40 AM
      |   view attached

    Hi guys,


    thanks for your reply. 


    We already paid a professional company to test our wifi network and they said that everything seems fine (with a big report). I could buy my own analyzing tools but, correct me if i'm wrong, heatmapper or testing tools are still testing the device reception and not the APs reception. I can crank up the power of my APs to the max but that is not going to help the device transmit power. I could do my test with an Android phone, but as we seen in the aruba Article, things are different between android and IOS.


    our config is;

    26x AP-105

    1x controller 3200XM

    Min Tx EIRP = 21


    About the aruba Article, it's based on iPhone 4 on 2.4Ghz, it's a lot different on 5Ghz (i don't think 802.11k & 802.11R are compatible with an iPhone 4). I know my config is well done, i had the help of Paul Galant an Aruba System Engineer here in Québec. 2.4Ghz is not appropriat for VOIP.


    Do you have any idea how i can measure my APs reception power from an IOS device? I'm not even sure if Airwave can do this, if it's possible i didn't see it.


    I attached a picture of my UCC, as you can see the controller thinks calls are good but it's not the reality.


  • 5.  RE: VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Sep 01, 2015 10:03 AM

    If Paul Galant is working with you, please continue to work with him.  You are in good hands...

  • 6.  RE: VOIP SIP on IOS (iPhone 5-6) bad SNR (5Ghz)

    Posted Sep 01, 2015 10:11 AM

    Paul is not "working" with me, i was lucky because the sales team didn't understand one of my questions, probably because of my bad english, and they transfert him to me. He review all my config and gave me some advices, but that's all.


    I had a bigger problem at that time, Bria for iPhone apps wasn't recognizing by the UCC. So he suggest me to open a ticket and i fixed it with the Aruba support team.