The Avaya 6400 Series multi-line telephone user guide provides setup, operation, and safety instructions for all 6400 models.
The 6400 Series includes the 6408+, 6408D+, 6416D+, 6416D+M, 6424D+, and 6424D+M multi‑line telephones. Each model offers a two‑way speakerphone, softkey menus, and optional headset or headpiece accessories. Models ending in “M” provide modular interface capabilities, while all units are hearing‑aid compatible (HAC).
The guide covers installation options (desktop, wall, and tray removal), designation‑card labeling, softkey feature usage, call‑handling functions such as conference, hold, and redial, and detailed tone meanings. Safety notices stress that the phones are for business use only and must be connected to a DEFINITY Enterprise Communications Server.
| Modular capabilities | Only 6416D+M and 6424D+M have modular interface capabilities |
|---|---|
| Hearing‑Aid Compatibility | All 6400‑Series telephones are HAC (Hearing Aid Compatible) |
| Residential use | Not for residential use; business systems only |
No. The guide states the telephone is NOT for residential use and is intended for business systems only.
Only the 6416D+M and 6424D+M models provide modular interface capabilities.
The designation card is used to label each call appearance/feature button with a telephone number, extension, name, or feature.
The 6424D+ model has 24 call appearance/feature buttons.