Common Networking Protocols
UDP
A connectionless, datagram service that provides an unreliable, best-effort delivery.
FTP
File transfer protocol is used for transferring files between remote systems. Must resolve host name to IP address to establish communication. It is connection oriented (i.e. verifies that packets reach destination).
ICMP
Internet Control Message Protocol enables systems on a TCP/IP network to share status and error information such as with the use of PING and TRACERT utilities.
IGMP
Internet Group Management Protocol is used to manage Internet Protocol multicast groups. IP hosts and adjacent multicast routers use IGMP to establish multicast group memberships. IGMP is only needed for IPv4 networks, as multicast is handled differently in IPv6 networks.
IMAP
Like POP3, Internet Message Access Protocol is a standard protocol for accessing e-mail from your local server. IMAP (the latest version is IMAP4) is a client/server protocol in which e-mail is received and held for you by your Internet server.
NTP
Network Time Protocol is a protocol that is used to synchronize computer clock times in a network of computers.
POP3
Post Office Protocol. A POP3 mail server holds mail until the workstation is ready to receive it.
TELNET
Provides a virtual terminal or remote login across the network that is connection-based. The remote server must be running a Telnet service for clients to connect.
RTP
Real-time Transport Protocol is the audio and video protocol standard used to deliver content over the Internet. RTP is used in conjunction with other protocols such as H.323 and RTSP.
TFTP
Same as FTP but not connection oriented.
HTTPS
Signifies that a web page is using the Secure Sockets Layer (SSL) protocol and is providing a secure connection. This is used for secure internet business transactions.
SIP
Stands for Session Initiation Protocol and is a signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol (IP). Other feasible application examples include video conferencing, streaming multimedia distribution, instant messaging, presence information and online games. The protocol can be used for creating, modifying and terminating two-party (unicast) or multiparty (multicast) sessions consisting of one or several media streams. The modification can involve changing addresses or ports, inviting more participants, adding or deleting media streams, etc.
SNMP
Stands for Simple Network Management Protocol and is used for monitoring and status information on a network. SNMP can be used to monitor any device that is SNMP capable and this can include computers, printers, routers, servers, gateways and many more using agents on the target systems. The agents report information back to the management systems by the use of "traps" which capture snapshot data of the system. This trap information could be system errors, resource information, or other information. The SNMPv2 standard includes enhancements to the SNMPv1 SMI-specific data types, such as including bit strings, network addresses, and counters. In SNMPv3 security was addressed. Because all of the trap information sent was in clear text, any monitoring information being sent and collected for operational purposes could also be pulled off the wire by a malicious person
TCP
TCP breaks data into manageable packets and tracks information such as source and destination of packets. It is able to reroute packets and is responsible for guaranteed delivery of the data.
HTTP
The Hypertext Transfer Protocol is the set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. It is the protocol controlling the transfer and addressing of HTTP requests and responses.
IP
This is a connectionless protocol, which means that a session is not created before sending data. IP is responsible for addressing and routing of packets between computers. It does not guarantee delivery and does not give acknowledgement of packets that are lost or sent out of order as this is the responsibility of higher layer protocols such as TCP.
TLS
Transport Layer Security is a cryptographic protocol that provides security for communications over networks such as the Internet. TLS and SSL encrypt the segments of network connections at the Transport Layer end-to-end. Several versions of the protocols are in wide-spread use in applications like web browsing, electronic mail, Internet faxing, instant messaging and voice-over-IP (VoIP).
SMTP
Used to reliably send and receive mail over the Internet.
ARP
provides IP-address to MAC address resolution for IP packets. A MAC address is your computer's unique hardware number and appears in the form 00-A0-F1-27-64-E1 (for example). Each computer stores an ARP cache of other computers ARP-IP combinations.