Speaker button mute is not working for AVAYA 6408D+...

Press it. There is a button below the headset button on the 5610, labeled MUTE.

You must have accidently hit the HFAns button on. If on your digital display you see a down arrown button on top of HFAns press the gray button on the bottom of HFAns. This will disable the handsfree option. Hope this solves your problem.

What kind of AT

The Mic/HFAI button mutes the microphone when on speaker.When the light on the mic button is off the microphone is muted and vice versa.

Mute the speaker, mute the ringing?

well.. we use a definity and i use site administration and on the station account its self i have a COR setup to restrict the phone from dialing out. if you want help and have the same system let me know.

You need to ask your local system administrator to enable this feature on phone switch. Looks like you are working with IP Office

If you are an administrator, you can make the change in the second page of the station "auto-answer=none". Otherwise, if you are user and there in in your menu list the feature int-auto-ans, you can press the specific button.
I hope to help you.

Phone system console. Contact your system admin, as it depends on exactly which system you have.

With the handset on the hook press the conf button (the one with three phones on it).

The phone should ring with your current ringtone. Each press of the conf button will advance to the next tone.

pick up the handset and put it down again to select the ringtone.

I think there are 8 to choose from.