ISO/OSI Models
Physical Layer
Data Link
Network Layer
Transport Layer
Session Layer
Presentation Layer
Application Layer
what describes the end-to-end principle?
nachschauen
What do the different layers care about communication wise?
they basically are only interested in the horizontally communication, not really what happens above and below…
What is the difference between PDU, SDU and SAP?
PDU: Protocol Data Unit -> header + SDU (PDU from one layer higher)
SDU : more or less the payload of a PDU
SAP: more or less the intersection between two layers -> conceptualized place where one layer can request services from another layer…
What are the network design decisions discussed?
no state between sender and destination
end-to-end principle
What are the different destinations possible?
unicast (single host destination)
broadcast (all hosts )
multicast ( group of selected hosts)
Are mac addresses specific for the medium?-
yes they are
-> e.g. ethernet/wlan 48 bit
is the mac address fixed?
yes -> stored by manufacturer on network card…
what are some reserved bits in mac addresses?
individual /Group (uni or broadcast)
1 bit globally or locally daministered
vendor and product information (first couple of bits identify vendor)
What is the OUI?
first octet of MAC
organizationally unique identifiers
-> assigned to manufacturers/vendors of networking equipment
Why are MAC addresses only used for next hop transportation?
not possible to have list of ALL possible mac addresses and where they are located…
=> thats what IP subnetting us used for…
What is the NDP used for?
host knows IP but wants MAC address of other host…
Is NDP protocol specific? If yes, what is the other?
NDP -> IPv6
ARP -> IPv4
Last changed2 years ago