starter (1261B)
1 The transport layer will format the packet with the send address and return address, this is the IP part of the protocol. It will package the data up in such a way that it can be sent down many different routes. The transport layer is the section that desides the route, sending many packets down different routes is called packet switching. 2 3 To act as a connection point for all the devices. 4 5 IMAP -- recives mail from the internet and stores it in a "mail box", this can be retrieved by many devices, allowing mail to be synced between them. 6 7 SMTP -- sends mail, will send it to another users mail box. 8 9 A well known port is a port that all applications implementing a spceific protocol will use. 10 11 This is to ensure that these applications are cross compatibe with eachother, and that communication can be automatic (no need to have a different port for every person you want to talk too). 12 13 Computer A has a private key 14 The email will be sent with a public key 15 The private key is used to encrypt the data 16 The public key can decrypt the data 17 Computer B will recive the email and attempt to decrypt it with the public key 18 If it can do this, then it means the email must have been sent from computer A 19 If not, then it couldn't have been sent from computer A