Cisco 7925 on Aerohive

  • 1
  • Question
  • Updated 3 years ago
  • Answered

I'm looking for some info from anyone who has experience (hopefully successful) running Cisco 7925g IP phones on Aerohive.  We have been struggling for some time with various issues and are trying to work all possible paths to resolve them.  Many of our problems are likely due to design issues (less than optimal placment of APs, etc.) which we are in the process of correcting with help from an outside partner.

Naturally we also need to determine if we have configured the Aerohive infrastructure optimally to support voice.  Unfortunately Aerohive support has not been able to provide us with much specific information for our Cisco phones as far as configuration for the best interoperability.  I've read through every post on this forum that I can find related to voice and have used much of the information I've found.  One thing I'm hoping someone might be able to shed some light on for me is regarding call admission control on Aerohive specifcally.  When I read the Aerohive documentation about enabling call admission control it only mentions SIP and Vocera voice traffic but our Cisco 7925g phones run Cisco's SCCP.  Will enabling CAC have any effect in this case?

Also, in 6.1x versions there are several new features related to "Voice Enterprise".  These relate to various 802.11 standards that our 7925g phones do support.  One of these items I'm not so clear on is the WMM Admission Control.  What is the difference between the WMM Admission Control (located in the Advanced settings for the SSID) and Call Admission Control (located under Advanced Configuration > Management Services > Management Options)?

Does anyone have any other advice specifically related to the Cisco 7925g on Aerohive?  Aerohive does not have an interop guide for this handset so I've been working from Cisco's 7925g Deployment Guide.  Cisco's guide is written for Cisco wireless, but much of the information is applicable to any system.

Any info would be appreciated as I'm trying not to leave any stone unturned.

Photo of Jerad Andrews

Jerad Andrews

  • 3 Posts
  • 0 Reply Likes

Posted 4 years ago

  • 1
Photo of Gary Smith

Gary Smith, Official Rep

  • 299 Posts
  • 61 Reply Likes
Hi Jerad,

I am going to refer to the help guide for my first try to answer your question.

The difference between WMM-AC and CAC - 


On the AP121, AP141, AP330, and AP350, WMM-AC uses QoS controls and bandwidth management techniques to augment existing WMM capabilities. It does this by monitoring the channel conditions and load to determine whether a device can support the traffic requested to be transmitted. If the device determines that the current channel conditions cannot support the extra traffic, then it will deny the traffic, causing the transmitting station to seek another path. If the channel conditions are determined to be healthy enough to support the extra traffic, then the device allows the traffic. In this way, WMM-AC prevents voice degradation due to channel conditions and management.

CAC (Call Admission Control) monitors the device resource load and airwaves for congestion, and then determines whether to allow additional VoIP (Voice over IP) calls—either SIP (Session Initiation Protocol) or Vocera—to initiate on that device. If the device and airwaves are already over-utilized, then the device does not allow callers to start new calls.  

Does this help?

Kind Regards,
Gary Smith
Photo of Jerad Andrews

Jerad Andrews

  • 3 Posts
  • 0 Reply Likes

Thanks Gary.  This information was largely the reason for my question.  I was able to speak with Mike Kouri and Krishna from product management on Friday and learned from them that in my case the "old" CAC in Aerohive will not be useful since our Cisco phones run SCCP.  Mike said that the CAC traffic inspection is indeed only looking for SIP (by message type) and Vocera (by port).  He indicated that the WMM AC would be useful in our case as it does not rely on traffic inspection but rather, as described in the documentation, on channel conditions.  This gives me a clear understanding of my options regarding admission control with thei Cisco 7925g/Aerohive combination.

The other questions I posed about advice for running Cisco 7925 phones on Aerohive remain.  Mike and Krishna said they did not know if an interop guide for the Cisco 7925 would be published at some point.  Like most things I imagine that will be based on customer demand.

Photo of Dario Facca

Dario Facca

  • 2 Posts
  • 0 Reply Likes
Hi Jerad and Gary,

We too are trying to setup 7925's on an Aerohive network.  Any ideas on the best settings for the phones, QoS, etc.

Thanks
Photo of Jerad Andrews

Jerad Andrews

  • 3 Posts
  • 0 Reply Likes

Hi Dario,

We continue to struggle with some issues with the 7925 on Aerohive but have seem some improvement from adjustments we've made.  My first recommendation would be to read Cisco's 7925 deployment guide if you haven't already as that will be your best resource for information on the handset.  On the wireless side, you'll be best served if you can keep your voice exlusively on 5GHz.  Unfortunately, if you're using the auto channel select feature in Aerohive on 5GHz, you'll need to move to a static channel plan as the 7925 does not support channel 165 and Aerohive provides no way to customize the auto channel list so you'll end up with holes in your coverage where APs choose this channel.  I've inquired about the ability to customize the auto channel list many times and Aerohive continues to say it's on the roadmap but has not indicated a target release for the feature.  Fortunately the QoS is fairly straight forward and Aerohive provides multiple options for how you can accomplish this on the wireless side.  If you have a dedicated SSID for voice, the simplest method would be to select "SSID" under Classifier Maps and configure your voice SSID for QoS class 6-Voice.  Otherwise you can configure Qos by service or  802.1p/DiffServ/802.11e.  Just make sure whatever you configure on the wireless side gets marked correctly when it hits the wired network.  If you're using Cisco and DiffServ on your wired network and you'll need to make sure things are mapped correctly in your Aerohive classifier and marker maps.  By default Cisco uses DSCP 46 for voice, but Aerohive will classify that as Video by default.

Again, I can't emphasize enough about the 7925 deployment guide.  It has been more helpful to me than any support Aerohive has been able to provide.

Photo of Dario Facca

Dario Facca

  • 2 Posts
  • 0 Reply Likes
Hi Jerad,

Thanks for the quick response.  We have been using the Cisco 7925 deployment guide and yes, very helpful.  We are going to try your suggestions as they make sense.  We are waiting on some more gear from Aerohive so we can setup a test environment.  I will let you know how it goes and any tricks/settings that we come across.
Photo of Paul Granberg

Paul Granberg

  • 1 Post
  • 1 Reply Like
Hi All,

  We have just deployed 7925G's throughout our business.  One thing that I have really found to be a performance/quality killer is 5Ghz band steering.
  Using Aerohive bandsteering with these units results in multiple reconnection attemtpts on 2.4Ghz as the APs try to 'steer' the 7925s to 5Ghz.  This results in a lot of dropped calls when roaming between APs because of the number of re-association attempts that are made.  What I have been seeing when roaming is:

1)  7925G powers up and connects on 5Ghz.
2)  As the handset is moves further from APs and the 5Ghz coverage drops off, it will try to reconnect on 2.4Ghz.
3) Bandsteering kicks in and tries to guide it back to 5Ghz (1st re-connection attempt)
4) Depending on your Radio Profile settings, you can have between 1-100 reconnection attempts before allowing a connection on 2.4Ghz. (more reconnection attemps and possible dropped calls depending on how this is set up)
5) The unit then successfully connects to the AP on 2.4Ghz
6)  The unit will then try to roam to the next AP, which then triggers another round of band steering until it can get a 2.4Ghz connection.
7)  Rinse and repeat.

  We have had to lock the units to 2.4Ghz to get the optimal balance of call quality and roaming.

  Also as mentioned above Channel 165 is not supported on these phones.  Using a pretty standard 5Ghz setup you will find that you will have holes in your coverage, and roaming will be severely affected where the AP selects 165 as the most appropriate channel. to use.

 Fortunately, using the supplementary CLI, there is a command you can send to all APs to exclude the use of Channel 165

interface wifi1 radio channel exclude 165

I have deployed it to our APs and none of them now select this channel when configuring themselves.

  I hope this helps.  The forum here has been a very good source of advice for me and I'm trying to give a bit back.