CS6250 - EXAM 1 QUESTIONS AND
ANSWERS
How=did=Licklider=and=his=team=in=the=early=1960s=experiment=with=a=precursor=to=the
=internet?=-=ans-✔✔Connecting=two=computers=over=a=dial-up=telephone=line
What=is=the=Domain=Name=System=(DNS)=designed=to=do=primarily?=-=ans-
✔✔Translate=domain=names=into=IP=addresses
What=is=the=architectural=design=of=the=Internet=protocol=stack=based=on?=-=ans-
✔✔Layers
T/F:=Both=the=data=link=and=transports=layer=protocols=may=provide=error=correction=-
=ans-✔✔True
What=allows=for=communication=between=the=applications=layer=and=the=transport=laye
r=-=ans-✔✔Sockets
Which=of=the=following=protocols=belong=to=the=application=layer?=[ethernet/DNS/UDP/
IP]=-=ans-✔✔DNS
Which=two=protocols=belong=to=the=transport=layer?=[IP/TCP/UDP/HTTP]=-=ans-
✔✔TCP,=UDP
When=an=application=sends=a=packet=of=information=across=the=network,=this=packet=tr
avels=down=the=IP=stack=and=undergoes=what=process=-=ans-✔✔Encapsulation
According=to=the=end-to-
end=principle,=where=should=most=of=the=Internet's=functionality/
intelligence=be=implemented?=-=ans-✔✔At=the=edges=of=the=network
What=is=the=difference=between=hubs,=bridges,=and=routers?=-=ans-
✔✔They=operate=on=different=layers=of=the=IP=stack
, T/F:=the=UDP=and=TCP=protocols=have=a=large=overlap=of=functionality=-=ans-✔✔false
T/
F:=the=transport=layer=protocols=offer=a=logical=connection=between=processes,=only=if=
the=hosts=reside=in=the=same=network=-=ans-✔✔false
T/
F:=a=sender=host=receives=a=message=from=the=application=layer=it=encapsulates=it=wit
h=the=transport=layer=header=before=passing=it=down=to=the=network=layer=-=ans-
✔✔true
T/F:=an=application=running=on=a=host=can=bind=to=multiple=sockets=simultaneously=-
=ans-✔✔true
T/F:=a=host=cannot=maintain=a=TCP=socket=and=a=UDP=socket=simultaneously=-=ans-
✔✔false
T/F:=the=identifier=of=a=UDP=socket=is=a=tuple=of=destination=IP=address=and=port=-
=ans-✔✔true
T/F:=the=identifier=of=a=TCP=socket=is=a=tuple=of=source=IP=address=and=port=-=ans-
✔✔false
T/F:=UDP=is=considered=more=lightweight=than=TCP=-=ans-✔✔true
T/
F:=when=two=hosts=use=UDP=to=send=and=receive=messages,=they=need=to=signal=the=
end=of=sending=data=to=each=other=when=they=are=done=-=ans-✔✔false
T/
F:=one=of=the=functionalities=that=UDP=offers=is=to=increase=or=decrease=the=pace=with
=which=the=sender=sends=data=to=the=receiver=-=ans-✔✔false
T/F:=UDP=offers=basic=error=checking=-=ans-✔✔true
T/
F:=assume=hosts=A,=B,=and=C.=Host=A=has=a=UDP=socket=with=port=123.=Hosts=B=and
=C=each=send=their=own=UDP=segment=to=Host=A.=Hosts=B=and=C=cannot=use=the=sa
me=destination=port=123=for=sending=their=UDP=segment=-=ans-✔✔false
T/F:=TCP=offers=in=order=delivery=of=packets,=flow=control,=and=congestion=control=-
=ans-✔✔true
T/F:=TCP=detects=packet=loss=using=timeouts=and=triple=duplicate=acknowledgements=-
=ans-✔✔true
ANSWERS
How=did=Licklider=and=his=team=in=the=early=1960s=experiment=with=a=precursor=to=the
=internet?=-=ans-✔✔Connecting=two=computers=over=a=dial-up=telephone=line
What=is=the=Domain=Name=System=(DNS)=designed=to=do=primarily?=-=ans-
✔✔Translate=domain=names=into=IP=addresses
What=is=the=architectural=design=of=the=Internet=protocol=stack=based=on?=-=ans-
✔✔Layers
T/F:=Both=the=data=link=and=transports=layer=protocols=may=provide=error=correction=-
=ans-✔✔True
What=allows=for=communication=between=the=applications=layer=and=the=transport=laye
r=-=ans-✔✔Sockets
Which=of=the=following=protocols=belong=to=the=application=layer?=[ethernet/DNS/UDP/
IP]=-=ans-✔✔DNS
Which=two=protocols=belong=to=the=transport=layer?=[IP/TCP/UDP/HTTP]=-=ans-
✔✔TCP,=UDP
When=an=application=sends=a=packet=of=information=across=the=network,=this=packet=tr
avels=down=the=IP=stack=and=undergoes=what=process=-=ans-✔✔Encapsulation
According=to=the=end-to-
end=principle,=where=should=most=of=the=Internet's=functionality/
intelligence=be=implemented?=-=ans-✔✔At=the=edges=of=the=network
What=is=the=difference=between=hubs,=bridges,=and=routers?=-=ans-
✔✔They=operate=on=different=layers=of=the=IP=stack
, T/F:=the=UDP=and=TCP=protocols=have=a=large=overlap=of=functionality=-=ans-✔✔false
T/
F:=the=transport=layer=protocols=offer=a=logical=connection=between=processes,=only=if=
the=hosts=reside=in=the=same=network=-=ans-✔✔false
T/
F:=a=sender=host=receives=a=message=from=the=application=layer=it=encapsulates=it=wit
h=the=transport=layer=header=before=passing=it=down=to=the=network=layer=-=ans-
✔✔true
T/F:=an=application=running=on=a=host=can=bind=to=multiple=sockets=simultaneously=-
=ans-✔✔true
T/F:=a=host=cannot=maintain=a=TCP=socket=and=a=UDP=socket=simultaneously=-=ans-
✔✔false
T/F:=the=identifier=of=a=UDP=socket=is=a=tuple=of=destination=IP=address=and=port=-
=ans-✔✔true
T/F:=the=identifier=of=a=TCP=socket=is=a=tuple=of=source=IP=address=and=port=-=ans-
✔✔false
T/F:=UDP=is=considered=more=lightweight=than=TCP=-=ans-✔✔true
T/
F:=when=two=hosts=use=UDP=to=send=and=receive=messages,=they=need=to=signal=the=
end=of=sending=data=to=each=other=when=they=are=done=-=ans-✔✔false
T/
F:=one=of=the=functionalities=that=UDP=offers=is=to=increase=or=decrease=the=pace=with
=which=the=sender=sends=data=to=the=receiver=-=ans-✔✔false
T/F:=UDP=offers=basic=error=checking=-=ans-✔✔true
T/
F:=assume=hosts=A,=B,=and=C.=Host=A=has=a=UDP=socket=with=port=123.=Hosts=B=and
=C=each=send=their=own=UDP=segment=to=Host=A.=Hosts=B=and=C=cannot=use=the=sa
me=destination=port=123=for=sending=their=UDP=segment=-=ans-✔✔false
T/F:=TCP=offers=in=order=delivery=of=packets,=flow=control,=and=congestion=control=-
=ans-✔✔true
T/F:=TCP=detects=packet=loss=using=timeouts=and=triple=duplicate=acknowledgements=-
=ans-✔✔true
