If your IP phones support LLDP-MED, this is your best bet. Check out the application note Configuring Link-Layer Discovery Protocol (LLDP) and LLDP-Media Endpoint Discovery (LLDP-MED) in AOS for configuration examples and in-depth info. Basically, you setup the feature on each switchport and a special VoIP-phone beacon is periodically sent out. When you connect an compatible IP phone, it detects the LLDP-MED beacon and self-configures to tag its own traffic with the VLAN number specified. There is no need to configure these switchports as trunks. LLDP-MED will automatically support 802.1Q VLAN trunk per port as phones come online. Data to/from devices connected to phone switches (pass through) will be un-tagged (default VLAN).
If your phones do not support LLDP-MED, I think the next-best choice would be to configure each switchport to be an 802.1Q trunk. In this scenario, you would need to configure your phones for the intended VLAN (tagging for self-sourced traffic).
There may be more than one way to handle the bridge over T1 for your 1335s. Generally, a routed WAN link is preferred to avoid broadcast traffic congesting low-bandwidth links. For this reason, it may be most desirable to setup your WAN to connect routed segments as normal (not wide-open bridge) and then leverage the Integrated Routing and Bridging (IRB) featue of AOS to select which traffic is routed and which is bridged. Guide: Configuring Bridging in AOS It's a hybrid approach that provides more granular control and improved broadcast domain boundary. That same guide covers legacy bridging too, if you think that would better fit your application.
Thank you, that was very helpful. - Jeremy
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