Difficulty "trunking" Brocade switch from Cisco

I'm aware that "trunking" is a Cisco thing, but that's the term I'm most familiar with to describe what I'm looking to accomplish--

I have an older Catalyst switch on IOS 15.0.2, and a Brocade ICX 6610. I want to "trunk" my voice VLAN (38) and my data VLAN (39) from the Cisco switch to the Brocade. My trunk on the Cisco side looks like:

interface GigabitEthernet0/20

switchport trunk encapsulation dot1q

switchport trunk native vlan 2

switchport trunk allowed vlan 38,39

switchport mode trunk

no mdix auto

Meanwhile, this is almost all of my Brocade config: (wow their "show run" output is tiny)

!

vlan 38 by port

tagged ethe 1/1/1 to 1/1/48

!

vlan 39 by port

tagged ethe 1/1/1 to 1/1/48

!

dot1x-mka-enable

!

interface ethernet 1/1/2

inline power

Eth 1 is my uplink, Eth 2 is my test port for the phone. VOIP functionality is much more important, so I haven't introduced "dual-mode" yet to risk complicating any troubleshooting further...

What else am I missing, assumedly on the Brocade end? Thanks so much for any assistance!