IP QoS Parameters
karthikbalaguru
I would like to know the field that conveys the QCI or
QoS in IP.
I am looking for a mapping of IP QoS Parameters
as below -
If QCI is 1 or 2, then it is "Conversational"
If QCI is 3 or 4, then it is "Streaming"
If QCI is 5 or 6, then it is "Interactive"
If QCI is 5 or 6, then it is "Background"
Any ideas, how the TOS can be used/mapped to get
the above QCI so that it can be used for the
derivation of QoS Parameters per PDP context.
From RFC 791,
" The Type of Service is used to indicate the quality
of the service desired.The type of service is an
abstract or generalized set of parameters which
characterize the service choices provided in the
networks that make up the internet. This type of
service indication is to be used by gateways to
select the actual transmission parameters for a
particular network, the network to be used for the
next hop, or the next gateway when routing an
internet datagram. "
" The Type of Service provides an indication of
the abstract parameters of the quality of service
desired. These parameters are to be used to
guide the selection of the actual service parameters
when transmitting a datagram through a particular
network. "
So, i thought TOS will give a clear info w.r.t
whether it is Conversational/Streaming/Interactive/
Background. But,it does not give that info in a
straightforward manner.
The TOS field appears to be of 8-bits and conveys
priority, delay, throughput and reliability but
does not explicity say the combination of such
fields or any particular field that would determine
whether it is either Conversational/Streaming
/Interactive/Background.
But, I need this to derive the QoS parameters
per PDP Context from the IP QoS parameters which
assumes that IP QoS Parameters will be of -
QCI 1 or 2 for 'Conversational'
QCI 3 or 4 for 'Streaming'
QCI 5 or 6 or 7 for 'Interactive'
else it is 'background'
Any ideas, how the TOS can be used/mapped to get
the above QCI so that it can be used for the
derivation of QoS Parameters per PDP context.
Thx in advans,
Karthik Balaguru
Albert Manfredi
wrote:
> So, i thought TOS will give a clear info w.r.t
> whether it is Conversational/Streaming/Interactive/
> Background. But,it does not give that info in a
> straightforward manner.
Nothing straightforward about QoS backfitting into IP networks.
There are different schemes out there, and I don't know that any one
has the corner on the IP QoS market. Possibly, ISPs can give you a
better feel than I can on that score, though.
The two basic schemes are IntServ (Integrated Services), RFC 2211 and
2212, and Diffserv (Differentiated Services), RFC 2474 and 2475. The
former is perhaps more what you're looking for, and comes in various
flavors (like RSVP), and the latter is more of an aggregated scheme,
to be used inside the ISP net, rather than a scheme to be used between
two hosts.
The IntServ scheme suffers from the fact that routers need to keep
state for all the QoS sessions.
Anyway, if you read those RFCs, you should get a better idea of how
variable the answer is to your question.
Bert
karthikbalaguru
> On Nov 28, 3:12 am, karthikbalaguru <karthikbalagur...@gmail.com>
> wrote:
>
> > So, i thought TOS will give a clear info w.r.t
> > whether it is Conversational/Streaming/Interactive/
> > Background. But,it does not give that info in a
> > straightforward manner.
>
> Nothing straightforward about QoS backfitting into IP networks.
>
True !
> There are different schemes out there, and I don't know that any one
> has the corner on the IP QoS market. Possibly, ISPs can give you a
> better feel than I can on that score, though.
>
> The two basic schemes are IntServ (Integrated Services), RFC 2211 and
> 2212, and Diffserv (Differentiated Services), RFC 2474 and 2475. The
> former is perhaps more what you're looking for, and comes in various
> flavors (like RSVP), and the latter is more of an aggregated scheme,
> to be used inside the ISP net, rather than a scheme to be used between
> two hosts.
>
> The IntServ scheme suffers from the fact that routers need to keep
> state for all the QoS sessions.
>
Agreed !
> Anyway, if you read those RFCs, you should get a better idea of how
> variable the answer is to your question.
>
Thx for your inputs.
I think it should be either IntServ with RSVP or
DiffServ. But, Diffserv seems to be the more preferred method as
IntServ suffers from the fact that the routers need to keep state for
all the QoS sessions.
Karthik Balaguru