Specifically, there should be a samba or file sharing service defined, where all the service ports are defined. Instead on a portion is defined under netbios-ssn (port 139).
Extract from this website (
http://troy.jdmz.net/samba/fw/)
Ports, Protocols, and Daemons
In the /etc/services file you will find a few lines that refer to Samba services:
netbios-ns 137/tcp # NetBIOS Name Service
netbios-ns 137/udp
netbios-dgm 138/tcp # NetBIOS Datagram Service
netbios-dgm 138/udp
netbios-ssn 139/tcp # NetBIOS Session Service
netbios-ssn 139/udp
microsoft-ds 445/tcp # Microsoft Directory Service
microsoft-ds 445/udp
The picture this provides is somewhat deceiving, since the half of those lines could be removed and condensed to:
netbios-ns 137/udp # NetBIOS Name Service
netbios-dgm 138/udp # NetBIOS Datagram Service
netbios-ssn 139/tcp # NetBIOS Session Service
microsoft-ds 445/tcp # Microsoft Directory Service