Position

Compatibility (check with sales for updates)

Amplified?

Wire Set

Note

A

Most Standard Telephones (Sangoma/NEC/Polycom/Panasonic/3-Com/Aastra/Escene/FANVIL)

NO

T+,R+,R-,T-

Normal wire sequence

B

Cisco IP Phones

NO

R+,T+,T-,R-

Cisco wire sequence

C

Ascom & Philips Phones

NO

R-,T+,R+,T-

Special wire sequence

D

Yealink/Avaya/HuaWei/Snom/ AKUVOX/GRANDSTREAM IP Phone

NO

T-,R+,R-,T+

Versa wire sequence

E

Yealink/Avaya/HuaWei/Snom/ AKUVOX/GRANDSTREAM IP Phone

YES/+9dB

T-,R+,R-,T+

Versa wire sequence amplification

F

Most Standard Telephones (NEC/Polycom/Panasonic/3- Com/Aastra/Escene/FANVIL)

YES/+9dB

T+,R+,R-,T-

Normal wire sequence amplification

G

Avaya Callmaster V&VI

YES/+9dB

R+,T+,T-,R-

Cisco wire sequence amplification