Hi all
Based on the suggestion of Jerry we have written an example on matching
the initiator QSPEC to a local RMD-QSPEC, see below!
We would like to include this section in Appendix A.6 of the new version
of the RMD-QOSM draft.
-------------------------
A.6. Example on matching the initiator QSPEC to the local RMD-QSPEC
Section 3.4 of [QSP-T] describes an example of how the QSPEC can be
used
within QOS-NSLP. Figure A.4 illustrates a situation where a QNI and a
QNR are using an end to end QOSM, denoted in this context as Z-e2e. It
is considered that the QNI access network side is a wireless access
network built on a generation "X" technology with QoS support as
defined
by generation "X", while QNR access network is a wired/fixed access
network with its own defined QoS support. Furthermore, it is considered
that the shown QNE edges are located at the boundary of a RMD domain
and
that the shown QNE Interior nodes are located inside the RMD domain.
The
QNE edges are able to run both the Z-e2e QOSM and the RMD-QOSM, while
the QNE interior nodes can only run the RMD-QOSM. The QNI that is
considered to e.g., be a wireless laptop, while the QNR a PC.
|------| |------| |------| |------|
|Z-e2e |<->|Z-e2e |<------------------------->|Z-e2e |<->|Z-e2e |
| QOSM | | QOSM | | QOSM | | QOSM |
| | |------| |-------| |-------| |------| | |
| NSLP | | NSLP |<->| NSLP |<->| NSLP |<->| NSLP | | NSLP |
|Z-e2e | | RMD | | RMD | | RMD | | RMD | | Z-e2e|
| QOSM | | QOSM | | QOSM | | QOSM | | QOSM | | QOSM |
|------| |------| |-------| |-------| |------| |------|
-----------------------------------------------------------------
|------| |------| |-------| |-------| |------| |------|
| NTLP |<->| NTLP |<->| NTLP |<->| NTLP |<->| NTLP |<->| NTLP |
|------| |------| |-------| |-------| |------| |------|
QNI QNE QNE QNE QNE QNR
(End) (Ingress Edge) (Interior) (Interior) (Egress Edge) (End)
Figure A.4. Example of Initiator & Local Domain QOSM Operation
The QNI sets QoS Desired and QoS Available QSPEC objects in the
initiator QSPEC, and initializes QoS Available to QoS Desired. In this
example, the <Minimum QoS> object is not populated. The QNI populates
QSPEC parameters to ensure correct treatment of its traffic in domains
down the path. Additionally, to ensure correct treatment further down
the path, the QNI includes <PHB Class> in <QoS Desired>. The QNI
therefore includes in the QSPEC
QoS Desired = <TMOD> <PHB Class>
QoS Available = <TMOD> <Path Latency>
In this example it is assumed that the <TMOD> parameter is used to
encode the traffic parameters of a VoIP application that uses RTP and
the G.711 Codec, see Appendix B in [QSP-T].
The below text is copied from [QSP-T].
"In the simplest case the Minimum Policed Unit m is the sum of the
IP-, UDP- and RTP- headers + payload. The IP header in the IPv4 case
has a size of 20 octets (40 octets if IPv6 is used). The UDP header
has a size of 8 octets and RTP uses a 12 octet header. The G.711
Codec specifies a bandwidth of 64 kbit/s (8000 octets/s). Assuming
RTP transmits voice datagrams every 20ms, the payload for one
datagram is 8000 octets/s * 0.02 s = 160 octets.
IPv4+UDP+RTP+payload: m=20+8+12+160 octets = 200 octets
IPv6+UDP+RTP+payload: m=40+8+12+160 octets = 220 octets
The Rate r specifies the amount of octets per second. 50 datagrams
Are sent per second.
IPv4: r = 50 1/s * m = 10,000 octets/s
IPv6: r = 50 1/s * m = 11,000 octets/s
The bucket size b specifies the maximum burst. In this example a
burst of 10 packets is used.
IPv4: b = 10 * m = 2000 octets
IPv6: b = 10 * m = 2200 octets ", from [QSP-T].
In our example we will assume that IPV4 is used and therefore, the
<TMOD-1> values will be set as follows:
m = 200 octets
r = 10000 octets/s
b = 2000 octets
The Peak Data Rate-1 (p) and MPS are not specified above, but in our
example we will assume:
p = r = 10000 octets/s
MPS = 220 octets.
The <PHB Class> is set in such a way that the Expedited Forwarding
(EF) PHB is used.
Since <Path Latency> and <QoS Class> are not vital parameters from
the QNI's perspective, it does not raise their M flags.
Each QNE, which supports the Z-e2e QOSM on the path, reads and
interprets those parameters in the initiator QSPEC.
When an end-to-end RESERVE message is received at a QNE Ingress node
at the RMD domain border then the QNE ingress can 'hide' the
initiator
end-to-end RESERVE message so that only the QNE edges process the
initiator (end-to-end) RESERVE message, which then bypasses
intermediate nodes between the edges of the domain, and issues its own
local RESERVE message (see Section 6). For this new local RESERVE
message, the QNE Ingress node generates the local RMD-QSpec. The
RMD-QSpec corresponding to the RMD-QOSM is generated based on
the original initiator QSPEC according to the procedures described in
Section 4.5 of [QoS-NSLP] and in Section 6 of this draft. The RMD QNE
ingress maps the <TMOD-1> parameters contained in the original
initiator
QSPEC into the equivalent <TMOD-1> parameter representing only the peak
bandwidth in the local RMD-QSpec.
In this example the initial <TMOD-1> parameters are mapped into the
RMD-QSpec <TMOD-1> parameters as follows.
As specified the RMD-QOSM bandwidth equivalent <TMOD-1> parameter of
RMD-QSpec should have:
r = p of initial e2e <TMOD-1> parameter
m = large;
b = large;
For the RMD-QSpec <TMOD-1> parameter the following values are
calculated:
r = p of initial e2e <TMOD-1> parameter = 10000 octets/s
m is set in this example to large as follows:
m = MPS of initial e2e <TMOD-1> parameter = 220 octets
The maximum value of b = 250 Gbytes, but in our example this value is
quite large. The b parameter specifies the extent to which the data
rate
can exceed the sustainable level for short periods of time.
In order to get a large b, in this example we consider that for a
period of certain period of time the data rate can exceed the
sustainable level, which in our example is the peak rate (p).
Thus in our example we calculate b as:
b = p * MPS * "period of time".
For this VoIP example, we can assume that this period of time is 1,5
seconds, see below:
b = 10000 octets/s * 220 octets * 1,5 seconds = 3300000 octets
Thus the local RMD-QSpec <TMOD-1> values are:
r = 10000 octets/s
p = 10000 octets/s
m = 220 octets
b = 3300000 octets
MPS = 220 octets
The local RMD QSPEC for example also needs <PHB Class>, which in this
example is representing the EF PHB class.
The RMD QNE egress node updates QoS Available on behalf of the entire
RMD domain if it can. If it cannot (since the M flag is not set for
<Path Latency>) it raises the parameter-specific, 'not-supported'
flag,
warning the QNR that the final latency value in QoS Available is
imprecise.
In the "Y" access domain, the initiator QSPEC is processed by the QNR
in the similar was as it was processed in the "X" wireless access
domain, by the QNI. If the reservation was successful, eventually the
RESERVE request arrives at the QNR (otherwise the QNE at which the
reservation failed would have aborted the RESERVE and sent an error
RESPONSE back to the QNI). If the RII was included in the QoS NSLP
message, the QNR generates a positive RESPONSE with QSPEC objects QoS
Reserved and QoS Available. The parameters appearing in QoS Reserved
are the same as in QoS Desired, with values copied from QoS Available.
Hence, the QNR includes the following QSPEC objects in the RESPONSE:
QoS Reserved = <TMOD> <PHB Class>
QoS Available = <TMOD> <Path Latency>
-------------
Best regards,
Georgios
On 3/2/2010, "Georgios Karagiannis" <karagian@xxxxxxxxxxxxx> wrote:
>Hi Jerry
>
>We will include in the Appendix a similar example as the one given in
>Section 3.4 of the QSPEC draft.
>
>Best regards,
>Georgios
>
>On 3/2/2010, "Gerald Ash" <gash5107@xxxxxxxxx> wrote:
>
>>One more comment:
>>
>>Section 3.1 of the QSPEC draft http://tools.ietf.org/html/draft-ietf-nsis-qspec-24#section-3.1 lists requirements for QOSM specifications including "QNE processing rules describing how QSPEC information is treated and interpreted"and "at least one bit-level QSPEC example".
>>
>>While the RMD draft has examples in Appendix A of individual processing functions, there is no overall, end-to-end example given of QSPEC composition and processing from QNI to QNR and back again. IMO this would greatly help an overall understanding of RMD functionality.
>>
>>Such QSPEC processing examples are given in Sections 4.4 ("Processing Example") and 4.5 ("Bit-Level QSPEC Example") of the Y.1541-QOSM draft (http://tools.ietf.org/html/draft-ietf-nsis-y1541-qosm-10#section-4.4)
>>and
>>Section 3.4 ("Example of QSPEC Processing") of the QSPEC draft (http://toolsietf.org/html/draft-ietf-nsis-qspec-24#section-3.4).
>>
>>Thanks,
>>Jerry
>>
>>--- On Mon, 3/1/10, Gerald Ash <gash5107@xxxxxxxxx> wrote:
>>
>>
>>From: Gerald Ash <gash5107@xxxxxxxxx>
>>Subject: Re: [NSIS] Last Call: draft-ietf-nsis-rmd (RMD-QOSM - The Resource Management in Diffserv QOS Model) to Experimental RFC
>>To: ietf@xxxxxxxx, nsis@xxxxxxxx
>>Cc: "Jerry Ash" <gash5107@xxxxxxxxx>
>>Date: Monday, March 1, 2010, 2:20 PM
>>
>>
>>
>>
>>
>>
>>
>>Minor editorial comments:
>>
>>1. page 35:
>>" the "Peak Data Rate-1 (p)" value of the <Bandwdith> parameter.
>> When the QNE edges use aggregated intra-domain QoS-NSLP operational
>> states, then the "Peak Data Rate-1 (p)" value of the <Bandwdith>"
>>substitute <TMOD-1> for <Bandwdith>
>>
>>2. page 101:
>>" directions by using the procedure described in Section 4.6.2.3 and
>> including in the <Bandwith> parameter within the "RMD-QOSM QOS
>> Description" field carried by the "forward" intra-domain RESERVE the"
>>substitute <TMOD-1> for <Bandwith>
>>
>>Thanks,
>>Jerry
>>
>>
>>--- On Mon, 3/1/10, The IESG <iesg-secretary@xxxxxxxx> wrote:
>>
>>
>>From: The IESG <iesg-secretary@xxxxxxxx>
>>Subject: [NSIS] Last Call: draft-ietf-nsis-rmd (RMD-QOSM - The Resource Management in Diffserv QOS Model) to Experimental RFC
>>To: "IETF-Announce" <ietf-announce@xxxxxxxx>
>>Cc: nsis@xxxxxxxx
>>Date: Monday, March 1, 2010, 9:38 AM
>>
>>
>>The IESG has received a request from the Next Steps in Signaling WG
>>(nsis) to consider the following document:
>>
>>- 'RMD-QOSM - The Resource Management in Diffserv QOS Model '
>> <draft-ietf-nsis-rmd-16.txt> as an Experimental RFC
>>
>>The IESG plans to make a decision in the next few weeks, and solicits
>>final comments on this action. Please send substantive comments to the
>>ietf@xxxxxxxx mailing lists by 2010-03-22. Exceptionally,
>>comments may be sent to iesg@xxxxxxxx instead. In either case, please
>>retain the beginning of the Subject line to allow automated sorting.
>>
>>The file can be obtained via
>>http://www.ietf.org/internet-drafts/draft-ietf-nsis-rmd-16.txt
>>
>>
>>IESG discussion can be tracked via
>>https://datatracker.ietf.org/public/pidtracker.cgi?command=view_id&dTag=12558&rfc_flag=0
>>
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