Radius and port 77

[Pascal Legrand]

Hello,
i'm using radius authentication (freeradius) on alcatel switchs and i 
can see in freeradius logs this kind of message :

Login OK: [XXXXXXXXXXXX/XXXXXXXXXXXX] (from client Switch port 77 cli 
XXXXXXXXXXXX)

Does someone could explain me what means "port 77"

As much I understand this notation :
Login OK: [XXXXXXXXXXXX/XXXXXXXXXXXX] (from client Switch port 1021)

As much i cant understand "port 77"

Thanks for your help
Pascal