Aastra Telecom 51i IP Phone - Manual (Page 17)

Model 51i IP Phone Installation Guide 11
Installation and Setup
Connecting a Handset
Handset
Turn the phone over and locate the handset jack marked j. Insert one
end of handset cord into the jack until it clicks into place. Then route the
handset cord through the groove as shown in the illustration below. Attach
the handset to the other end of the handset cord.
Handset