TCP/UDP
- What is the purpose of the transport layer?
To transfer data. Letting
multiple applications use one network connection simultaneously.
- How is the PDU (protocol data unit) called in the transport layer?
In the Transport Layer it’s
called Segment.
- What has to be done before the PDU from the transport layer is passed to the network layer?
It contents information
about the source and the destination.
- Why can packets containing UDP be much smaller than that containing TCP?
UDP is connection less, it
does not need the system. You have more control when the data is sent.
- What is the main characteristic of a connection-oriented transmission?
They use the three-way Hand
shake system. The packets are always received in the correct order and error
free. This is possible by sending acknowledges back to the sender. If it isn't,
the sender will try to send it again.
- What happens at UDP and TCP when a segment gets corrupted?
UDP delete it, or he saves
it and say I can’t be opened.
TCP sends it again.
TCP sends it again.
- What happens in UDP when an older segments arrives after a newer one?
It is normal displayed,
because UDP don’t know how is the older segment.
- Explain the term "congestion control". What does it mean when a network is "congested"?
It helps to minimize packet
loss.
- Is the checksum mandatory in UDP?
The checksum is only by
IPv6 mandatory.
- Which disadvantages does TCP show over UDP?
o
The TCP header is bigger than the UDP header.
o
Data doesn’t always send out immediately this is a side effect of
congestion control.
o
TCP must establish a connection.
- Which transport layer protocol is used in real-time communication applications (Skype, VoIP)?
Skype uses The TCP Protocol
on the ports 80 and 443.
VoIP uses the UDP Protocol,
because it’s simpler and there is no delay of data.
- What's the difference between a stream oriented and a message oriented protocol?
Message oriented protocols send
data in distinct chunks or groups. The receiver of data can determine where one
message ends and another begins. Stream protocols send a continuous flow of
data.
- When is it better to use TCP rather than UDP?
TCP is better for stremming.
TCP is also need, when you
don’t want to lose Data.
1. File
transfers
2. Remote
access
- TCP three-way Hand shake
1. The host sends a request to the other host to build up
a connection
2. The other
host sends his answer. When it’s a yes.
3. The host sends another packet to build up the
connection
The connection must be closed after the transmission.
The connection must be closed after the transmission.
