• ak23
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  • Registered: 2024-01-02
  • Posts: 4

Topic: 802.1AS device priority

Hello,

using 12Mic, 12Mic is elected Grandmaster. This causes a desirable situation where 12Mic is Master for audio and gPTP clock.

However, when connecting some Apple Thunderbolt 2 Ethernet adapters to the network, the network elects new Grandmaster (newly connected MAC computer). This situation is not acceptable. Also it causes all other devices on the network to resynch to new Grandmaster causing audio interruption. This is also unacceptable as any computer reboots would cause entire audio network crash for few seconds.

How it is possible to modify 12Mic network adapter settings to set Priority 1 and Priority 2 parameters so that some network adapters would not cause Grandmaster changes?

P.S. While this would probably be a new feature you need to make, can you also make so that 12Mic could have Static IP settings?

  • Max
  • Max
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  • Registered: 2007-05-09
  • Posts: 319

Re: 802.1AS device priority

Hi ak23,

please install the newest firmware, static IP adddresses have already been added.

Regarding the election of gPTP grandmaster: unless using Netgear switches (M4250 series cannot act as grandmaster), I would recommend using the switch as gPTP grandmaster, which wins the election or provides corresponding priority settings that you mention. If not, re-test for audio dropouts and report this to support (Apple and/or us), because AVB by itself has mechanisms to ensure that streams do not get interrupted even if the grandmaster changes while streaming.

Adding settings to AVB defeats its great benefit of being plug'n'play, so it is better we find out the root cause why your audio gets interrupted when the GM changes. Please send your exact setup with firmwares of devices , stream configuration and a recording of the audio dropout to our support so that it can be reproduced and investigated. Please note that Apple is not AVB or MILAN certified by AVNU, also not much is revealed or documented about their AVB implementation, so we can only describe the symptoms and - in case this needs to be improved on Apple's side - we can only report the issue to them.

Best regards,
Max
RME