Transport layer of the OSI model

GHOSTRIDER2016GHOSTRIDER2016 Member Posts: 35 ■■□□□□□□□□

I have been having a look at the OSI model and what I find perplexing is that. Apparently end to end transmission occurrs at the transport layer. So am i right in saying that the packet will be encapsulated with the the appropriate headers in the datalink and network layers then the sole function of the transport layer is to get that newly wrapped up packet to the destination machine ? using the mac address and ip address headers.



  • FillAwfulFillAwful Member Posts: 119 ■■■□□□□□□□
    I Think of it like this: As you go up the the OSI stack you peel away layers of the packet from outer to inner frames (wireshark illustrates this well). The transport layer is concerned with Transport Protocols like TCP and UDP.

    When a packet traverses a network the packets are read or changed, or even stripped away, by devices (routers, switches and firewalls) outside to inside.

    Layer 2 Data link (ARP, Mac address) read by the switch, to the router (Network Layer) IPv4, IPv6, to the firewall (Transport layer, Ports) and finally to the different application layers (Session data and application data like SSL, HTTP, DNS). The reverse process for incoming packets.

    Hope this helps.
  • amcnowamcnow Member Posts: 215 ■■■■□□□□□□
    To sum things up, encapsulation (i.e., adding headers and/or footers) occurs when moving down the OSI stack. Decapsulation (i.e., stripping headers and/or footers) occurs when moving back up the OSI stack.
    WGU - Master of Science, Cybersecurity and Information Assurance
    Completed: JIT2, TFT2, VLT2, C701, C702, C706, C700, FXT2
    In Progress: C688
    Remaining: LQT2
    Aristotle wrote:
    For the things we have to learn before we can do them, we learn by doing them.
Sign In or Register to comment.