Multicast Bonjour issues

[anchor]

A client has several Apple TVs and other Apple devices that cannot see each other now that we are on the 160.  I there something special I need to turn on to allow that broadcast traffic to hit other wireless clients in the same Vlan?

This post was the closest I could find... How come Apple Bonjour (Formerly Rendezvous) is unable to locate devices and services that are on th...

The two devices trying to find each other are both connected to the same wireless vlan on the same device...

Thanks!

[Anonymous]

I'm interested in this question too.  Looking forward to the answer.    In our experience, an iOS device connected to an NV160 AP functions properly with a hard-wired Apple TV.  But we cannot connect to an Apple TV that is also connected via WiFi with an NV160 AP.

[Anonymous]

:

Thank you for asking this question in the support community.  Multicast traffic can be problematic for wireless networks as it is a low priority protocol and will be queued at the access point (AP). This is true for all 802.11 technologies. When editing a specific radio on an AP in the web interface, there will be a tab to display advanced settings. Within the advanced settings there are settings for the beacon period (or the command beacon period <time> in the CLI).  Most likely, this setting will need to be changed.

Beacons are sent by the AP to keep the wireless network synchronized. The delivery traffic indication message (DTIM) will alert the wireless clients of the presence of broadcast and multicast traffic. After the DTIM, the access point will send the broadcast/multicast traffic. These settings are set to 100ms for the beacon interval and 1 for the DTIM by default. In other words, the default settings are to send broadcast/multicast traffic every 100ms. Often times this will cause the application to fail as it appears there is no connectivity.

Beacon frames are associated with some overhead, which decreases the throughput of the wireless network. The higher the beacon period, the fewer number of beacons sent, thus reducing overhead and increasing throughput on the network. However, fewer beacons can cause a delay in the association process because stations scanning for available access points (APs) may miss the beacons.  The DTIM is set to one, so the unit will send an indicator with each beacon. The beacon interval however is default at 100ms, so that would be the first thing to modify (lower). I do not recommend configuring this for less than than 50ms though. Otherwise the AP doesn't have enough capabilities to service very many clients. Essentially the lower the interval, the less clients that AP can properly support.

Levi

[anchor]

levi:

Ok, I've changed the DTIM value to 60ms.  Is there a ball park idea of how many clients it can support at what DTIM value?  We were previously on a Cisco WAP4410 before upgrading to the NV160 and it didn't have these issues.  Is there something special it was doing?

I'll update with the result tomorrow when the devices are back to work.

Thanks!

[anchor]

Levi:

Changing the value several times hasn't worked.  What else can we try?

Thanks!

[Anonymous]

:

Approximately how many clients are connected to each NV160?  A packet capture on one of the clients may be beneficial to see how much multicast traffic is on the network and if there are large bursts because the multicast traffic is getting queued.  Is it possible for you to reply with a copy of the configuration? Please, remember to remove any information that may be sensitive to the organization.

Levi

[Anonymous]

For what it's worth, our company's president and CFO have a NetVanta 1335 at their home with one NetVanta 160 WAP.  They don't have a whole lot of network hosts or much traffic going on; almost no multicast.  We have been messing with this for quite a while and can't seem to figure it out.  Their (sanitized) config is attached.

The results are consistent, 100% of the time:  Any WiFi-connected Apple TV is unusable; only wired Apple TVs can be accessed.

[Anonymous · Accepted solution]

:

Thank you for adding this to the thread.  The problem you have described has be corrected in a firmware release for the NetVanta 160 (6.5.5-16).  The release notes describe the issue as follows:

• Resolved an issue where Apple AirPlay would not function correctly when connected to a NetVanta 16x.

After you upgrade the firmware, please let me know if you still experience any issues.

Levi

[anchor]

levi,

Thank you sir!  I can confirm that the latest  firmware fixes the issues we had.

Thanks,

Ryan

[Anonymous]

Took us a while to get back to this, but the new firmware corrected the issue in our case too.  We found the article Upgrading Firmware on an ADTRAN Netvanta 160 Series Unit in Recovery Mode to be super helpful during the upgrade process.  Thanks!