MR42's and Cisco 7921 IP phones not playing nicely

Bossnine
Building a reputation

MR42's and Cisco 7921 IP phones not playing nicely

First let me say I know, the 7921's are ancient and outdated but unfortunately we still have them in use.  I don't think they are great to begin with but they were usable until we migrated to Meraki Wifi in our schools. 

 

They connect, they show up in call manager, and technically work; however, all too often one person or another cannot hear the other end. 

 

I spoke with Cisco Tac about it and they will not even assist due to the age of the phone.  Meraki support was very helpful in helping me fine tune some voice settings on the SSID but it never really solved the issue completely. 

 

Does anyone else out there run this combination?  I feel like they do in that due to the age is it even worth them fighting it, but its what we have. 

15 REPLIES 15
ww
Kind of a big deal
Kind of a big deal

the call drops or is it 1 way call from the beginning? and this happens sometimes or every time? you are running bridged mode or Layer 3 roaming , and did hou try both modes? 

Bossnine
Building a reputation

I wouldn't say the call drops, it actually stays connected but you can't hear anything from either end.

 

It doesn't happen everytime, which makes it very difficult to diagnose.  I would say 50% of the time.

 

I am running bridged mode, haven't tried Layer 3 roaming (not really sure what the different seems to be between those two anyway).

 

 

BrandonS
Kind of a big deal

Are you on v25 or v26 on the MR?  I have had some voip troubles with one way audio related to 802.11k handling that is probably not the same as your issue by similar. I have also read somewhere that default QOS policy might cause issues for voip. 

so I would try v25 with qos policy off if you have not already. 

Best. 

- Ex community all-star (⌐⊙_⊙)
cmr
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Kind of a big deal

I hate to be the bearer of bad news but Cisco Wi-Fi phones don't play nicely with Meraki wireless.

 

We had 7921s, 7925s and 8821s when we started moving to Meraki a few years ago from old Cisco WLCs and 1242s.  We had random frequent one way audio on all of them initially and in the last year we finally got 7925s to behave unless you let them go to sleep when they won't ring...  Last week we installed the latest firmware on our 8821s and the one way audio, though still occasionally happening is definitely much better.  We have been on 25.13 since it was released and I believe this is what got the 7925s (sort of) working.  We tried 26.2 in production as it seemed okay at our HQ but it was a big fail in the venues with regular occasions where suddenly dozens of clients (iPads and Cisco Wi-Fi phones) would lose connectivity and not get it back unless we rebooted the AP.  We currently are running 25.14 in the venues but are yet to know how stable that is.

 

If you haven't already tried, then Cisco Wi-Fi phones definitely like to be on lightly loaded radios (no more than 10 clients) and prefer 5GHz, though I'm not sure this applies to the 7921 as I can't remember if it had it!  We have only the phones, Wi-Fi security radios and our iPads on the 5GHz radios and this means they seldom go over 10 clients.  The rest of the users have to all squeeze on the 2.4GHz radio, but I've seen that working with 100+ phones/laptops!

cmr
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Oh and you only need L3 roaming if the same SSID has varying VLANs behind it - i.e. SSID phone goes to VLAN 97 on one AP and VLAN 98 on a different one in the same campus.

 

Finally if you use 802.1x instead of PSK the roaming time is supposed to decrease from 0.5s to 0.1s

PhilipDAth
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Kind of a big deal

Some of my thoughts - this sounds like a roaming issue;

  • Make sure you are using bridge mode.
  • Disabled 802.11r (if used).
  • Disable client load balancing in the RF profile.
Bossnine
Building a reputation


@PhilipDAth wrote:

Some of my thoughts - this sounds like a roaming issue;

  • Make sure you are using bridge mode.
  • Disabled 802.11r (if used).
  • Disable client load balancing in the RF profile.

 

I will verify those configurations but I believe that is what I have set.  I agree that it seems like a roaming issue,.

cmr
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Kind of a big deal


@Bossnine wrote:

@PhilipDAth wrote:

Some of my thoughts - this sounds like a roaming issue;

  • Make sure you are using bridge mode.
  • Disabled 802.11r (if used).
  • Disable client load balancing in the RF profile.

 

I will verify those configurations but I believe that is what I have set.  I agree that it seems like a roaming issue,.


We found that though there are always (minor) roaming issues, for the Cisco 8821s at least, that the one way audio can happen when continuously on a single AP, no deassociate etc. and the audio comes back 15-30 seconds later even while staying still...

Bossnine
Building a reputation


@cmr wrote:

@Bossnine wrote:

@PhilipDAth wrote:

Some of my thoughts - this sounds like a roaming issue;

  • Make sure you are using bridge mode.
  • Disabled 802.11r (if used).
  • Disable client load balancing in the RF profile.

 

I will verify those configurations but I believe that is what I have set.  I agree that it seems like a roaming issue,.


We found that though there are always (minor) roaming issues, for the Cisco 8821s at least, that the one way audio can happen when continuously on a single AP, no deassociate etc. and the audio comes back 15-30 seconds later even while staying still...

 

 

 


Yea, some of my occurrences may be roaming but generally they are teachers in a classroom at their desk........

 

But you are saying with the 8821's and the latest firmware it helped, correct?

cmr
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Kind of a big deal


@Bossnine But you are saying with the 8821's and the latest firmware it helped, correct?

Yes with 8821 firmware 11.0.5SR1 we are seeing certainly much better results though we haven't had it long enough to know if it effectively cures it...

Bossnine
Building a reputation


@cmr wrote:

@Bossnine But you are saying with the 8821's and the latest firmware it helped, correct?

Yes with 8821 firmware 11.0.5SR1 we are seeing certainly much better results though we haven't had it long enough to know if it effectively cures it...


Thanks, I appreciate any help or info you all have given.

Bossnine
Building a reputation


@cmr wrote:

Oh and you only need L3 roaming if the same SSID has varying VLANs behind it - i.e. SSID phone goes to VLAN 97 on one AP and VLAN 98 on a different one in the same campus.

 

Finally if you use 802.1x instead of PSK the roaming time is supposed to decrease from 0.5s to 0.1s


 

 

Thanks, never knew that

Bossnine
Building a reputation

And that may be the issue, currently a majority of our clients are on 5Ghz as we are a school with 1:1, so every classroom could have 30 clients at any given time and that's where the teacher is using the phone.  I want to say they are using the phone in planning periods but I don't have that data, definitely something I gather more info on.

 

With your 8821's how often does it fail now?  50%?  25% etc? 

cmr
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Kind of a big deal


With your 8821's how often does it fail now?  50%?  25% etc? 


It is more like 5% in initial testing as opposed to 50% of calls before, actually anything longer than 5 minutes would have an issue.

 

I did mean to do some more testing at another of our sites today but there was too much else to do...

 

I'll let you know once we have more stats.

Bossnine
Building a reputation

I am running 25.13, which is the up to date version.  I do have some QoS policies set that you'd think would improve it, I could try removing that and testing.

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