Re: Cisco 8821 telephone fails to register on call manager with qos 'platinum' profile

Arjen K · ‎01-10-2018

We are using Cisco 8821 (sip8821.11-0-3SR6-15) telephones on a test environment, 5508 wireless lan controller, firmware 8.2.166.0.

When I switch the Qos profile from 'Silver (best effort)' to 'Platinum (voice)', the 8821 phone will not register anymore on the callmanager. The phone is still icmp reachable! Changing the QoS profile back to 'Silver', and the phone starts with call manager registration again.

If I change the 'Maximum Priority', 'Unicast Default Priority', 'Multicast Default Priority' within the QoS 'platinum' policy from 'voice' to 'best effort', registration is also possible. Somehow the 'voice' priority breaks SIP registration.

Qos Profile Info

Description...................................... For Voice Applications
Maximum Priority................................. voice
Unicast Default Priority......................... voice
Multicast Default Priority....................... voice
Per-SSID Rate Limits............................. Upstream Downstream
Average Data Rate................................ 0 0
Average Realtime Data Rate....................... 0 0
Burst Data Rate.................................. 0 0
Burst Realtime Data Rate......................... 0 0
Per-Client Rate Limits........................... Upstream Downstream
Average Data Rate................................ 0 0
Average Realtime Data Rate....................... 0 0
Burst Data Rate.................................. 0 0
Burst Realtime Data Rate......................... 0 0
protocol......................................... dot1p
dot1p............................................ 6

The WLAN profile:

(Cisco Controller) >show wlan 5

WLAN Identifier.................................. 5
Profile Name..................................... TEST-VOIP-3
Network Name (SSID).............................. TEST_VoIP
Status........................................... Enabled
MAC Filtering.................................... Disabled
Broadcast SSID................................... Enabled
AAA Policy Override.............................. Disabled
Network Admission Control
Client Profiling Status
    Radius Profiling ............................ Disabled
     DHCP ....................................... Disabled
     HTTP ....................................... Disabled
    Local Profiling ............................. Disabled
     DHCP ....................................... Disabled
     HTTP ....................................... Disabled
  Radius-NAC State............................... Disabled
  SNMP-NAC State................................. Disabled
  Quarantine VLAN................................ 0
Maximum number of Associated Clients............. 20
Maximum number of Clients per AP Radio........... 20
ATF Policy....................................... 0
Number of Active Clients......................... 1
Exclusionlist.................................... Disabled
Session Timeout.................................. 36000 seconds
User Idle Timeout................................ Disabled
Sleep Client..................................... disable
Sleep Client Timeout............................. 720 minutes
User Idle Threshold.............................. 0 Bytes
NAS-identifier................................... none
CHD per WLAN..................................... Disabled
Webauth DHCP exclusion........................... Disabled
Interface........................................ to-vlan-1
Multicast Interface.............................. Not Configured
WLAN IPv4 ACL.................................... unconfigured
WLAN IPv6 ACL.................................... unconfigured
WLAN Layer2 ACL.................................. unconfigured
mDNS Status...................................... Disabled
mDNS Profile Name................................ unconfigured
DHCP Server...................................... Default
DHCP Address Assignment Required................. Disabled
Static IP client tunneling....................... Disabled
Tunnel Profile................................... Unconfigured
PMIPv6 Mobility Type............................. none
    PMIPv6 MAG Profile........................... Unconfigured
    PMIPv6 Default Realm......................... Unconfigured
    PMIPv6 NAI Type.............................. Hexadecimal
    PMIPv6 MAG location.......................... AP
Quality of Service............................... Platinum
Per-SSID Rate Limits............................. Upstream	Downstream
Average Data Rate................................   0		  0
Average Realtime Data Rate.......................   0		  0
Burst Data Rate..................................   0		  0
Burst Realtime Data Rate.........................   0		  0
Per-Client Rate Limits........................... Upstream	Downstream
Average Data Rate................................   0		  0
Average Realtime Data Rate.......................   0		  0
Burst Data Rate..................................   0		  0
Burst Realtime Data Rate.........................   0		  0
Scan Defer Priority.............................. 4,5,6
Scan Defer Time.................................. 100 milliseconds
WMM.............................................. Required
WMM UAPSD Compliant Client Support............... Disabled
Media Stream Multicast-direct.................... Disabled
CCX - AironetIe Support.......................... Enabled
CCX - Gratuitous ProbeResponse (GPR)............. Disabled
CCX - Diagnostics Channel Capability............. Disabled
Dot11-Phone Mode (7920).......................... Disabled
Wired Protocol................................... 802.1P (Tag=6)
Passive Client Feature........................... Disabled
Peer-to-Peer Blocking Action..................... Disabled
Radio Policy..................................... 802.11a only
DTIM period for 802.11a radio.................... 2
DTIM period for 802.11b radio.................... 2
Radius Servers
   Authentication................................ Disabled
   Accounting.................................... Disabled
   Dynamic Interface............................. Disabled
   Dynamic Interface Priority.................... wlan
Local EAP Authentication......................... Disabled
Radius NAI-Realm................................. Disabled
Mu-Mimo.......................................... Enabled
Security

   802.11 Authentication:........................ Open System
   FT Support.................................... Disabled
   Static WEP Keys............................... Disabled
   802.1X........................................ Disabled
   Wi-Fi Protected Access (WPA/WPA2)............. Enabled
      WPA (SSN IE)............................... Disabled
      WPA2 (RSN IE).............................. Enabled
         TKIP Cipher............................. Disabled
         AES Cipher.............................. Enabled
      OSEN IE.................................... Disabled
      Auth Key Management
         802.1x.................................. Disabled
         PSK..................................... Enabled
         CCKM.................................... Disabled
         FT-1X(802.11r).......................... Disabled
         FT-PSK(802.11r)......................... Disabled
         PMF-1X(802.11w)......................... Disabled
         PMF-PSK(802.11w)........................ Disabled
         OSEN-1X................................. Disabled
      FT Reassociation Timeout................... 20
      FT Over-The-DS mode........................ Enabled
      GTK Randomization.......................... Disabled
      SKC Cache Support.......................... Disabled
      CCKM TSF Tolerance......................... 1000
   Wi-Fi Direct policy configured................ Disabled
   EAP-Passthrough............................... Disabled
   CKIP ......................................... Disabled
   Web Based Authentication...................... Disabled
   Web Authentication Timeout.................... 300
   Web-Passthrough............................... Disabled
   Mac-auth-server............................... 0.0.0.0
   Web-portal-server............................. 0.0.0.0
   Conditional Web Redirect...................... Disabled
   Splash-Page Web Redirect...................... Disabled
   Auto Anchor................................... Disabled
   FlexConnect Local Switching................... Enabled
   FlexConnect Central Association............... Disabled
   flexconnect Central Dhcp Flag................. Disabled
   flexconnect nat-pat Flag...................... Disabled
   flexconnect Dns Override Flag................. Disabled
   flexconnect PPPoE pass-through................ Disabled
   flexconnect local-switching IP-source-guar.... Disabled
   FlexConnect Vlan based Central Switching ..... Disabled
   FlexConnect Local Authentication.............. Disabled
   FlexConnect Learn IP Address.................. Enabled
   Client MFP.................................... Optional
   PMF........................................... Disabled
   PMF Association Comeback Time................. 1
   PMF SA Query RetryTimeout..................... 200
   Tkip MIC Countermeasure Hold-down Timer....... 60
   Eap-params.................................... Disabled
AVC Visibilty.................................... Enabled
AVC Profile Name................................. Voice
Flex Avc Profile Name............................ None
Flow Monitor Name................................ None
Split Tunnel Configuration
    Split Tunnel................................. Disabled
Call Snooping.................................... Disabled
Roamed Call Re-Anchor Policy..................... Disabled
SIP CAC Fail Send-486-Busy Policy................ Enabled
SIP CAC Fail Send Dis-Association Policy......... Disabled
KTS based CAC Policy............................. Disabled
Assisted Roaming Prediction Optimization......... Disabled
802.11k Neighbor List............................ Disabled
802.11k Neighbor List Dual Band.................. Disabled
802.11v Directed Multicast Service............... Disabled
802.11v BSS Max Idle Service..................... Enabled
802.11v BSS Transition Service................... Disabled
802.11v BSS Transition Disassoc Imminent......... Disabled
802.11v BSS Transition Disassoc Timer............ 200
802.11v BSS Transition OpRoam Disassoc Timer..... 40
DMS DB is empty
Band Select...................................... Disabled
Load Balancing................................... Disabled
Multicast Buffer................................. Disabled
Universal Ap Admin............................... Disabled

 Mobility Anchor List
 WLAN ID     IP Address            Status                             Priority
 -------     ---------------       ------                             --------

802.11u........................................ Disabled

MSAP Services.................................. Disabled

Local Policy
----------------
Priority  Policy Name
--------  ---------------

Lync State ...................................... Disabled
Audio QoS Policy................................. Silver
Video QoS Policy................................. Silver
App-Share QoS Policy............................. Silver
File Transfer QoS Policy......................... Silver

Is there a way to configure/check the settings used for the priorities? I cannot find them, are they hardcoded in the controller

Leo Laohoo · ‎01-10-2018

dot1p............................................ 6

Can you try with dot1p value set to "5"?

Arjen K · ‎01-10-2018

I have tested the value 0, 5 and 6. All of them fail with registration.

Leo Laohoo · ‎01-10-2018

For Platinum, the 802.1p should be set to "5".
I think I know what's going on: The 8821's radio is prone of "crashing". If the phone goes in and out of a radio "zone" it has a high risk chance of "crashing". When this happens mortal people, like you and me, won't see this crashing event and won't know about it. The radio would "seem" to be still searching for the SSID.
The only way around this is to reboot the phone.
If this isn't the case, can you get a debug of the phone attempting to join the SSID?

Arjen K · ‎01-11-2018

Thanks for the update with explenation, this could be the cause why the 8821 roam so badly in our production environment. I also found out why it was set to 802.1p="6":

Note: In versions before Version 7.5, it was recommended to set the .1p tag to 6 for voice (although this would actually mark it with CoS 5 in reality). Versions after Version 7.5 default to 5 for platinum .1p. This is a cosmetic change only, behavior stays the same.

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/voice-over-wireless-lan-vowlan/116056-technote-qos-00.html

It seems it's less cosmetic if using the 8821. A lot of websites still promote the 802.1p= "6" settings as best practice!

For the test environment I will make the debug trace, maybe some other settings also break the 8821.

Freerk Terpstra · ‎01-21-2018

Setting the 802.1p values on the QoS profiles is not required since AireOS 8.0. If you don't specify 802.1p values, DSCP values will be used instead. Just make sure that you trust DSCP on the uplinks of the WLC.

Are you using 802.11n based access-points like the 2600 or 3600? I have ran into issues where the 8821 dropped its registration due to using A-MSDU frame-aggregation on the 4th queue; even with the most recent versions of code. In case you are using 802.11n based access-points I recommend you to test with A-MSDU disabled:

config 802.11a disable network
config 802.11a 11nSupport a-msdu tx priority all disable
config 802.11a enable network

Please rate useful posts... :-)

Arjen K · ‎01-30-2018

Hi Freerk,

Long time no see :)

A-MSDU TX is already disabled:

(WLC01) >show 802.11a 
    A-MSDU Tx:
        Priority 0............................... Disabled
        Priority 1............................... Disabled
        Priority 2............................... Disabled
        Priority 3............................... Disabled
        Priority 4............................... Disabled
        Priority 5............................... Disabled
        Priority 6............................... Disabled
        Priority 7............................... Disabled

Still the problems remain. We are planning to upgrade to 8.2.166 and file a TAC-case...

Regards,

Arjen

Freerk Terpstra · ‎01-30-2018

Hi Arjan,

Indeed, time flies when you're having fun... :-)

I have seen decent performance with your current software versions (SR6.15 and 8.2.166.0). Which hardware are you using on the wireless side?

Are there any pointers visible during a "debug client"? If not, my advice is to put an access-point in sniffer mode and make traces during the issue. It would be great if you could share your traces here, in case this isn't possible please do up-date the topic afterwards with the findings of TAC for others as reference.

Please rate useful posts... :-)

Saravanan Lakshmanan · ‎01-19-2018

what DSCP values on CM were set. Phone will not send the packets over the air if the DSCP is set anything other than CS3.

kbeelwar · ‎05-09-2018

Hi,

Can you pls let me know what the resolution to this case was through TAC. I am running into similar issue.

Arjen K · ‎05-11-2018

Hi,

In the end we have the following changes:

- Set all telephones to sip8821.11-0-3SR6 firmware.

- Upgraded the wlc (8510) to 8.2.166.

- Configured SIP profile for 8821 in callmanager.

- Set Qos profiles for platinum to 802.1p=5.

After the wlc firmware upgrade the solution works reasonable stable. We still think it's not fully solved, however. But the problem isn't reproducible, so hard to troubleshoot.

Do you also use traffic shaping on wifi profiles? And do you have audio problems? half-way audio?