Controllerless Networks

Dear community, I am facing an issue with a project recently implemented and I am hoping for some pointers if at all possible in terms of diagnosing and hopefully remedying the issue if its a network problem. The network solution comprises of a HPE Aruba 2920 Switch stack with Aruba 225 access points and a number of networked multimedia presentation devices.

The client environment comprises of a number of collaboration / meeting spaces, users connect to the corporate WIFI (ARUBA instant 225 cluster) and once connected to the network, users are able to access a  networked presentation devices for each area which sit on the LAN. The presentation devices are WePresent WIPG 2000’.(http://www.wepresentwifi.com/) which basically allow PC / MAC and mobile devices to perform screen mirroring to a high definition display for the purposes to presentation / collaboration using an app called MirrorOp presenter.

When the users connect and authenticate to the wireless network, the access point drops them on to one of a number of VLANS hosted on the Aruba 2920 stack. VLAN 20 for admin personnel. VLAN 30 for member personnel and VLAN 50 for guests. The network presentation devices reside in VLAN 60.

What the client is experiencing is what appears to them to be performance related issues (stuttering video and audio) when playing video content from a connected wireless device. Screen mirroring using the presentation devices works well otherwise.

Aruba instant virtual controller shows excellent connection speeds (dependant on client), the switch shows relatively low port utilisation when video presentation is taking place. The wireless network is in very good health with AP’s showing low utilisation and all green lights in terms of interference, client connection speed etc. There are no network restrictions or bandwidth contracts in place and clients are able to obtain maximum possible connection speeds and throughput on the local network.

The AP’S are connected to the Switch stack with LACP (2 x 1Gbe uplinks), the wireless presentation devices are 1Gbe and connect to the 2920’s.

The network is under low utilisation, just a handful of people on there, surfing the web etc. There are no errors / packet loss reported by the switch.

As you can appreciate the finger is beginning topoint at the network and I am keen to ensure this is eliminated as a cause.

Please does anyone have any experience of working with such multimedia presentation devices combined with Aruba switches and AP’s, are there perhaps any specific configuration settings recommended within the IAP or 2920’s for this type of multimedia use case. Are there any recommendations you can perhaps make in terms of investigating / diagnosing this, any hep appreciated.

Are you using the wireless WePresent model?

With regards to your network and realtime video, it is not the bandwidth, but the delay that is probably influencing your presentation.  Is there any priority in the network applied to prioritize the wepresent traffic at this time?

Do you have broadcast filtering in the Advanced portion of your SSID configuration?

Hi Colin, Thanks for your reponse. Yes the WePresent is the wireless model (WiPG 2000) however its integrated wireless radio is disabled as the clients connect using the Aruba IAP's so they can both present and also access the LAN / WAN. The WePresent is connected to the 2920 switch via its 1Gbe port.

All boradcast / multicast features under advanced settings are all disabled.

I did begin to look at the WMM settings / QOS DSCP tagging, however this happens when there is little or nothing happenong on the network, hence why this issue is particularly frustrating.

Okay.  Are the clients on the same VLAN as the WePresent?

Hi Colin, the WePresent devices reside on an AV VLAN - VLAN 60, the users reside on either VLAN 20 for Admin Personnel - VLAN 30 for member personnel or VLAN 50 guest. The VLANs are hosted on the 2920 switch stack, the IAP determines VLAN placement of users within the appropriate VLAN based on their 802.1x username composition.

Okay.  We should first  try to enable "Broadcast Filter ARP" under the SSID> Advanced configuration of all SSIDs on the IAP.  This will eliminate any of the contention that broadcast traffic might bring.

OK Colin, so that's the top option under broadcast / multicast "Broadcast
filtering", currently set to "disabled", will change this to Enabled.



I had also previously configured WMM 20% Background, 10% Best Effort, 70%
video. So will just leave this as is for now. (DSCP mapping is left blank)



Thanks for your guidance thus far.

With regards to the WMM, if the operating system or application is not tagging wifi frames (typically) it is not, those WMM parameters might not have any meaningful effect. Turn on broadcast filter to ARP and see if that makes a difference.

Hi Colin, thank you for the suggestion, I will make the configuration change
and will advise accordingly.



Best Regards

Hi Colin,

I attended the customer site today to undertake a troubleshooting exercise. I can confirm that the cause of the problem has been identified and I am pleased to say this is not related to the Aruba network components. Infact, the network  (wired and wireless) is performing very well when montitoring the switch utilisation and aruba instant VC under all test conditions.

 

I did however enable some device level QOS on the Aruba 2920 switch so that the wireless presentation gateway traffic is identified as 802.1p video priority using the follwing example command:

 

qos dev 10.2.60.40 priority 5

 

The issue has actually turned out to be caused by the MirrorOP client software and WePresent device struggling with the decode / encode / decode with screen mirroring when client screen resolution is high and high quality video content with lots of motion is played.

 

The latest generation of macbooks and PC laptops have very high resolution display output and evidently the screen mirroring has been struggling to keep up with the video content. The screen mirroring works very well for nomal presentations (powerpoint slides) but whenever motion picture is introduced at high res display settings we are seeing stuttering. The solution is to lower the screen res to something sensible e.g 1366 x 768 and it works very well.

 

Thanks for your assistance with this.