Controllerless Networks

Hi all,

We have been facing a few problems with a VoIP device running SIP and HFA, calls on that device have a very poor quality of voice reception but you can hear the devices trasnmitted voice properly. We are also facing a few problems with lost of registration. Below the technical information of the enviroment.

 

Aruba Instant AP Cluster Version 8.3.0 with models:
IAP 303 (RW)
IAP 305 (RW)
IAP 365 (RW)

 

SSID is a Voice SSID that we created with the following settings:
wlan ssid-profile WLAN-WIFI101
enable
index 7
type voice
essid wifi101
wpa-passphrase 00f631c638556a8f824fcbc249574387246324cd9171dd8b
opmode wpa-psk-tkip,wpa2-psk-aes
max-authentication-failures 0
vlan 101
rf-band 2.4
captive-portal disable
dtim-period 1
broadcast-filter all
g-min-tx-rate 5
dmo-channel-utilization-threshold 90
local-probe-req-thresh 0
max-clients-threshold 254
wmm-voice-dscp "46"
wmm-voice-share 85
dot11k

VoIP device:
Siemens Optipoint WL2 professional SIP version 70.000.081
Siemens Optipoitn WL2 proferrional HFA version 50.002.097

This device uses WPA for key management and TKIP for security.

There's also a DSCP tag on it for voice traffic with a priorization 46
We've also made a custom Roaming configuration for it setting the "Roaming Threshold" for 50dbm.

Nothing seems to be effective.

 

We've already made contact with the device's manufacture, and everything seems ok with their side.

 

I've opened a case with Aruba HPE, but it is a intermittent case, they were not able to troubleshoot properly remotetly.

 

Has anyone ever seen a problem with this voip Devices? They worked fine with Enterasys Access Points.

 

It would be nice if someone could help.

Br.,

Have you done a wireless packet capture on the channel and ensured that the client is receiving as well as sending prioritized packets when on a call?

Hi cjoseph

We've made a few captures with the TAC and we were able to see the QoS marks on the RDP packets according to the DSCP tag configured as i've mentioned.

I forgot to mention that we also have 2 other device models and everything seems fine with them.

On our researches we found a post on cisco blog about that same device.
https://community.cisco.com/t5/other-wireless-mobility-subjects/wlc-and-siemens-wl2-ip-phone/td-p/1000656

It is pretty much the same behavior on our network with Aruba IAP.

Hi,

have you tried to disable dot11k?

 

Here you will find recommendations regarding WLAN configuration:

https://wiki.unify.com/wiki/Recommendations_for_site_survey

Minimal data rate which should be maintained at the cell boarder

802.11g Network = 12 Mbps 802.11b Network = 11 Mbps

That brings the Client to a better Access Point, when he is at the boarder area of the cell.

Antenna Diversity

All Access Point antennas should use diversity.

Give it a try. Something you have to configure on CLI:

(Instant AP) (config) # wlan ssid-profile Name
(Instant AP) (SSID Profile "Name") # temporal-diversity
(Instant AP) (SSID Profile "Name") # max-retries 3

 

At what Signal Strenght and SNR do you see the phones connected?

Have you done User Debugging?

Hi cordless,

 

Sorry for the delay on the answer.

We've made the change on the dot11k, and raised the minimum bandwidth to 11Mbps. None of these changes made any improvement on the call quality of the WL2 handset.

 

We've tried to create another SSID with just WPA-TKIP for test purposes, but also no improvements.

 

We are still figuring out how to try the Diversity in an Airwave monitored/configured environment. Can you provide any tips on how to make it happen in Airwave's Instant GUI?

 

About the Signal Strenght and SNR, the phones usually connect at 30dBm and -12dBm, but I could even see phones connected with 0 on both values.

---

@cordless wrote:

Hi,

have you tried to disable dot11k?

 

Here you will find recommendations regarding WLAN configuration:

https://wiki.unify.com/wiki/Recommendations_for_site_survey

Minimal data rate which should be maintained at the cell boarder

802.11g Network = 12 Mbps 802.11b Network = 11 Mbps

That brings the Client to a better Access Point, when he is at the boarder area of the cell.

Antenna Diversity

All Access Point antennas should use diversity.

Give it a try. Something you have to configure on CLI:

(Instant AP) (config) # wlan ssid-profile Name
(Instant AP) (SSID Profile "Name") # temporal-diversity
(Instant AP) (SSID Profile "Name") # max-retries 3

 

At what Signal Strenght and SNR do you see the phones connected?

Have you done User Debugging?

---

---

@cordless wrote:

Hi,

have you tried to disable dot11k?

 

Here you will find recommendations regarding WLAN configuration:

https://wiki.unify.com/wiki/Recommendations_for_site_survey

Minimal data rate which should be maintained at the cell boarder

802.11g Network = 12 Mbps 802.11b Network = 11 Mbps

That brings the Client to a better Access Point, when he is at the boarder area of the cell.

Antenna Diversity

All Access Point antennas should use diversity.

Give it a try. Something you have to configure on CLI:

(Instant AP) (config) # wlan ssid-profile Name
(Instant AP) (SSID Profile "Name") # temporal-diversity
(Instant AP) (SSID Profile "Name") # max-retries 3

 

At what Signal Strenght and SNR do you see the phones connected?

Have you done User Debugging?

---

 

Hi guys,

 

After a few tests on our network, it seems like we've found the main issue here.

 

The fact is that the WL2 disconnections were occurring in specific IAP transitions, and we've noticed that these IAPs weren't in the same switch. So basically when we do roaming on IAPs that lay on the same switch everything seems fine but when they change to an IAP on another switch (even on the same cluster) the device loses connection. This is happening with all of the devices on the network which is also the cause of the WL2 failures.

 

We are using Fortinet Fortiswitches managed by Fortigate, and speaking with the Fortinet reseller it seems like the switch has to receive the clients IP nor the APs MAC in order to complete roaming outside the switch.

I've opened a new Topic for this issue if you guys can cooperate here's the link:https://community.arubanetworks.com/t5/Controllerless-Networks/IAP-L2-Roaming-issue-on-Fortinet-Network/td-p/517385

 

Thank you all for your insights