Friday 12 July 2013

Protocol vs Service

Just think HTTP, FTP, SMTP, PPP,  SLIP, SNMP, etc these should be treated as Protocol or Service? or which one is protocol & which one is service? In computer networking sometime it's become challenge to identify Protocols and services and it's not wise to remember this list so let's discuss some point which can help us to differentiate protocols and services . as we know we can define these two terms as follows:-

Protocol - Set of rules
Service - Serving something

from above definition it's quite simple that all services should be treated as protocols as without following rules it's not possible to deliver a service but reverse is not true all protocols aren't a service, to make this more simpler we can take reference of OSI & DOD/TCP model that anything which goes beyond Transport layer should be service and below transport layer it should be protocol or in short we can say "when protocol got mapped with a port no. it becomes service else it should be treated as protocol" as we know port no. is related to transport layer and anything which is going beyond transport should be using port no whether it's TCP port or UDP port and bellow transport we don't have ports. let's get back to our original discussion and check if this article help us to identify them correctly
HTTP, FTP, SMTP, & SNMP - all these protocols are using certain port so they should be categories as Service where PPP & SLIP should be categorize as Protocol as they work without port.

I hope it will help you to understand protocol and service in computer networking. :-)