TCP Port 139 Information

Port name:NetBIOS
Port 139 common errors:Any machine with NetBIOS and is not properly configured has high possibilty of contamination. To learn more about errors in your system run a free registry scan.
Services or applications using this port:NetBIOS Session service
Malicious services / applications:MS Technet Security Bulletin MS03-026, W32.HLLW.Moega, W32.Raedana.A, W32.Crowt.A@mm

Port 139 details:

Protocol: TCP
IAMA status: Official
Range: Well-known
Traffic: inbound, outbound, both
Notification: N/A
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Technical description for port 139:

The port 139 is defined as NetBIOS Session service that allows two machines to establish a link for a conversation. Unlike Datagram service, the NetBIOS Session Service permits bigger capacity of data messages to be handled. It also offers error recovery and detection. This service works on TCP port 139 in NetBIOS in TCP/IP or NBT.
Session service covers call services like calls for opens sessions on a remote and attempting to listen on an open a session to a NetBIOS name. it also closes sessions, sends packet to a machine on other end of a session, send Ack and receives waiting packets arrived from sent sessions.
Information is broadcasted during a created session by information packets which responded to each ACK or negative acknowledgment packet (NACK). Because NetBIOS is conducting error recovery, the NACK packet determinately prompts retransmission of the information packet. Sessions are clogged by the non-responding machine by transporting a secure request. The machine tracking the session will respond with a secure response to promptly close the final session.
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