QOS in a network with wireless IP phones CP-8821

leam2 · ‎05-16-2018

Hello,

My question is about QOS in a network with wireless IP phones CP-8821.

Configuration has been made on the Wi-fi access point:

WLAN 1
  SSID: ssid_1
  VLAN: 10
  qos : platinum (voice)

WLAN 2
  SSID: ssid_2
  VLAN: 50
  qos : silver (best effort)

The two WLANs, the two VLANs, the two associations WLAN-VLAN have been made on a Wi-fi WLC-AP (AIR-AP1832I-E-K9).

The Wi-fi WLC-AP is connected to a switch (Cisco Catalyst WS-C2960L-24TS-LL).

The switch is connected to an ISR4331.

I am wondering how qos is handled as traffic goes through the switch first and then through the isr.
If there is configuration to be made on the switch and on the isr, can you point me in the right direction?

Thank you.

leam2 · ‎05-16-2018

Hello again.

Just trying to clarify my question:

When a phone connects to WLAN 1 using SSID ssid_1,
traffic flowing through this wireless link is prioritized
given we've associated QOS platinum priority to WLAN 1.

(AIR-AP1832I-E-K9 Cisco Controller) >config wlan qos 1 platinum

The traffic arrives on the switch the Wi-fi AP is connected to.
Does this traffic still have QOS platinum priority?

After the traffic leaves the switch to go to the router,
does it still have this QOS platinum priority?

Can I suppose that as long as traffic coming from a phone "remains" in the LAN, it is prioritized over other traffic (traffic coming from machines on VLAN 50)?

After that, traffic can be sent outside of the LAN and then I've read about "service-policy", "policy-map", "class-map"... settings that have to be made on the ISR4331.

patoberli · ‎05-16-2018

Yes, Yes, No :)
You have to configure QoS on every active network device, meaning on the Switches and the Routers if you want to have the traffic handled with priority by those devices. Have a read about 'auto-qos'.
The question is, do you need QoS on the Switches and Routers, or have they more than enough spare bandwidth. In those cases you could start without QoS on them and see how it performs.
If you have a Mobility Express AP (I think the 1832 is one), also have a look into the AVC feature: https://www.cisco.com/c/en/us/td/docs/wireless/access_point/mob_exp/1/best_practices/b_ME_Best_Practices_Guide/infrastructure.html
That would allow you to utilize the same SSID for voice and data and still have the voice traffic prioritized. I think the separate SSID way is the better one though, but I'm not sure here.

leam2 · ‎05-16-2018

Thank you.

(Cisco Controller) >show ap config general AP0045.6813.7AC7
[...]
Cisco AP Type.................................... MobilityExpress Capable AP

patoberli · ‎05-17-2018

Ah yes, mobility express. I suggest you configure it through the webinterface, although not all features are available there.

leam2 · ‎05-17-2018

Hello.

I am focusing on the switch (Cisco Catalyst WS-C2960L-24TS-LL) here.

I have an example of configuration:

SWITCH interface Gi 0/1:
switchport mode access
switchport access vlan 50
switchport voice vlan 10

I think this config. corresponds to the case where a computer is connected to a phone which is in turn connected to the switch on port Gi 0/1 with wires between them all:

computer --------- phone --------- Gi 0/1 switch
            wire            wire

I am not in this case.
Below is my case:

              air, ssid_2, best effort
computer_1   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
              air, ssid_2, best effort
computer_2   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
              air, ssid_1, platinum           Wi-fi AP ---------- Gi 0/1 switch
8821_phone_1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~                 wire
              air, ssid_1, platinum
8821_phone_2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cisco CP-8821 wireless phones connect to a Cisco Wifi AP (AIR-AP1832I-E-K9) which in turn is connected via a wire to the switch on port Gi 0/1.

Computers can also connect to the Wifi AP.

Phones use ssid_1, vlan 10 with qos platinum.

Computers use ssid_2, vlan 50 with qos best effort.

So, I need to configure the Gi 0/1 switch switchport for that architecture.

Also, I noticed the following thing:

switch# show mls qos
QoS is disabled
QoS dscp rewrite is enabled

switch# show mls qos interface gi 0/1
GigabitEthernet0/1
QoS is disabled. When QoS is enabled, following settings will be applied
trust state: not trusted
trust mode: not trusted
trust enabled flag: dis
COS override: dis
default COS: 0

Shall I enable QoS globally:

switch(config)# mls qos

And/or for the interface Gi 0/1:

switch(config)# interface gigabitethernet0/1
switch(config-if)# mls qos trust cos

Can you provide the command lines to configure the switchport Gi 0/1 on the switch for this architecture with a Wi-fi AP?

Thank you.

patoberli · ‎05-17-2018

I sadly can't, because I've never configured it.
But you get some information about the switch configuration (without QoS) here for your deployment: https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-6/b_cisco_mobility_express_8_6.pdf
Check the start of Chapter 2, in your case it's the Trunk based deployment.
Regarding QoS, have a read here:
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960l/software/15-2_5_e/config-guide/b_1525e_consolidated_2960l_cg/b_1525e_consolidated_2960l_cg_chapter_011010.html