Subject: PROTO-08: Selection Sequence Statistics Report Interpretation

From: Benoit Claise <[email-masked]>
Date: Wed, 01 Mar 2006 23:13:55 +0100

Dear all,

Here is a text proposal for the issue 8

PROTO-08 Instead of sending the input sequence number for each 
   selector ID, a counter64 value, associated with every packet, the 
   working group should discuss the possibility to send the information 
   on regular basis with an option template record. Specifically in the 
   case of Composite Selector, we would send multiple times a 64-bit 
   counter in each packet. 

Regards, Benoit.

7.4.3    Selection Sequence Statistics Report Interpretation
A Selector MAY be used in multiple Selection Sequences.  However, each 
use of a Selector must be independent, so each separate logical instance 
of a Selector MUST maintain its own individual Selection State and 
statistics.

The Selection Sequence Statistics Report Interpretation MUST include the 
number of observed packets (Population Size) and the number of packets 
selected (Sample Size) by each instance of its Primitive Selectors.
Within a Selection Sequence composed of several Primitive Selectors, the 
number of packets selected for one Selector is equal to the number of 
packets observed by the next Selector.  The order of the Selectors in 
the Selection Sequence Statistics Report Interpretation MUST match the 
order of the Selectors in the Selection Sequence.
For every Selection Sequence, the PSAMP Device MUST periodically export 
a Selection Sequence Statistics Report Interpretation using an Options 
Template containing the following Information Elements:
 Scope:         selectionSequenceId
 Non-scope:  packetsObserved
                     packetsSelected (first)
                     ...
                     packetsSelected (last)
 
The packetsObserved Information Element [PSAMP-INFO] MUST contain the 
number of packets seen at the Observation Point, and as a consequence 
passed to the first Selector in the Selection Sequence.  The 
packetsSelected Information Element [PSAMP-INFO] contains the number of 
packets selected by a Selector in the Selection Sequence.
 
The Attained Selection Fraction for the Selection Sequence is calculated 
by dividing the number of observed packets (packetsObserved Information 
Element) by the value of selected packets (packetsSelected Information 
Element) for the last Selector.  The Attained Selection Fraction can be 
calculated for each Selector by dividing the number of packets selected 
for that Selector by the value for the previous Selector.
 
The statistics for the whole sequence SHOULD be taken at a single 
logical point in time, the input value for a Selector MUST equal the 
output value of the previous selector.
 
The Selection Sequence Statistics Report Interpretation MUST be exported 
periodically[CSI1] .
 
Example of Selection Sequence [CSI2] Statistics Report Interpretation:
 
 Selection Sequence 7 (Filter->Sampling):
 
   Observed   100  (observationPointId  1, Interface 5)
   Selected    50  (selectorId  5, match IPV4SourceAddress 10.0.0.1)
   Selected     6  (selectorId 10, Sampler: Random one out-of ten)
 
 Selection Sequence 9 (Sampling->Filtering):
 
   Observed   100  (observationPointId  1, Interface 5)
   Selected    10  (selectorId 10, Sampler: Random one out-of ten)
   Selected     3  (selectorId  5, match IPV4SourceAddress 10.0.0.1)
 
IPFIX Options Template Record:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            Set ID = 3         |           Length = 26         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Template ID = 267       |        Field Count = 4        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Scope Field Count = 1     |0|  selectionSequenceId = 301  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Scope 1 Length = 4       |0|    packetsObserved = 318    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Field Length = 4        |0|    packetsSelected = 319    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Field Length = 4        |0|    packetsSelected = 319    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Field Length = 4        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The associated IPFIX Data Record:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Set ID =  267       |          Length = 36          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               7                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              100                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              50                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               6                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               9                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              100                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              10                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               3                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 

    Figure K: Example of the Selection Sequence Statistics 
Report            
              Interpretation
             
Notes:
* The Attained Packet Fractions for Selection Sequence 7 are:
         Filter 10: 50/100
         Sampler 5: 6/50
         Number of samples selected: 6
 
* The Attained Packet Fractions for Selection Sequence 9 are:
         Sampler 5: 10/100
         Filter 10: 3/10
         Number of samples selected: 3

7.3.1 Basic Packet Reports
    
For each selected packet, the Packet Report MUST contain the following 
information:
- The selectionSequenceId Information Element
- Some number of contiguous bytes from the start of the packet, 
including the packet header (which includes link layer, network layer 
and other encapsulation headers) and some subsequent bytes of the packet 
payload.  Alternatively, the number of contiguous bytes may start at the 
beginning of the payload. The dataLinkFrameSection, 
mplsLabelStackSection, mplsPayloadPacketSection, ipPacketSection, and 
ipPayloadPacketSection PSAMP Information Elements are available for this 
use. 

In the Packet Report, the PSAMP device MUST be capable of exporting the 
number of observed packets and the number of packets selected by each 
instance of its Primitive Selectors (as described by the non scope 
Information Element of the Selection Sequence Statistics Report 
Interpretation) although it MAY be a configurable option not to include 
them. If exported, the Attained Selection Fraction may be calculated 
precisely for the Observed Packet Stream. The Packet Report MAY include 
only the final selector packetSelected, to act as an index for that 
selection sequence in the Selection Sequence Statistics Report 
Interpretation, which also allows the calculation of the Attained 
Selection Fraction.

The contiguous Information Elements ...

---

From: Juergen Quittek <[email-masked]>
Date: Thu, 02 Mar 2006 16:03:18 +0100

>    case of Composite Selector, we would send multiple times a 64-bit

I think we should be open for both ways of reporting, i.e. we should
allow an implementation to have all counters in each record as well as
to send current counter values in option records only now and then.

I will send detailed comments on the text below tonight.

Thanks,

    Juergen

> A Selector MAY be used in multiple Selection Sequences.  However, each use of a Selector must be independent, so each separate logical instance of a Selector MUST maintain its own individual Selection State and statistics.
>
> The Selection Sequence Statistics Report Interpretation MUST include the number of observed packets (Population Size) and the number of packets selected (Sample Size) by each instance of its Primitive Selectors.
> Within a Selection Sequence composed of several Primitive Selectors, the number of packets selected for one Selector is equal to the number of packets observed by the next Selector.  The order of the Selectors in the Selection Sequence Statistics
> Report Interpretation MUST match the order of the Selectors in the Selection Sequence.
> For every Selection Sequence, the PSAMP Device MUST periodically export a Selection Sequence Statistics Report Interpretation using an Options Template containing the following Information Elements:
> The packetsObserved Information Element [PSAMP-INFO] MUST contain the number of packets seen at the Observation Point, and as a consequence passed to the first Selector in the Selection Sequence.  The packetsSelected Information Element [PSAMP-INFO]
> contains the number of packets selected by a Selector in the Selection Sequence.
>
> The Attained Selection Fraction for the Selection Sequence is calculated by dividing the number of observed packets (packetsObserved Information Element) by the value of selected packets (packetsSelected Information Element) for the last Selector.  The
> Attained Selection Fraction can be calculated for each Selector by dividing the number of packets selected for that Selector by the value for the previous Selector.
>
> The statistics for the whole sequence SHOULD be taken at a single logical point in time, the input value for a Selector MUST equal the output value of the previous selector.
>
> The Selection Sequence Statistics Report Interpretation MUST be exported periodically[CSI1] .
>
>     Figure K: Example of the Selection Sequence Statistics Report
>               Interpretation
>
> Notes:
> For each selected packet, the Packet Report MUST contain the following information:
> - Some number of contiguous bytes from the start of the packet, including the packet header (which includes link layer, network layer and other encapsulation headers) and some subsequent bytes of the packet payload.  Alternatively, the number of
> contiguous bytes may start at the beginning of the payload. The dataLinkFrameSection, mplsLabelStackSection, mplsPayloadPacketSection, ipPacketSection, and ipPayloadPacketSection PSAMP Information Elements are available for this use.
>
> In the Packet Report, the PSAMP device MUST be capable of exporting the number of observed packets and the number of packets selected by each instance of its Primitive Selectors (as described by the non scope Information Element of the Selection
> Sequence Statistics Report Interpretation) although it MAY be a configurable option not to include them. If exported, the Attained Selection Fraction may be calculated precisely for the Observed Packet Stream. The Packet Report MAY include only the
> final selector packetSelected, to act as an index for that selection sequence in the Selection Sequence Statistics Report Interpretation, which also allows the calculation of the Attained Selection Fraction.
>

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---

From: Benoit Claise <[email-masked]>
Date: Thu, 02 Mar 2006 16:58:10 +0100

Juergen,
> allow an implementation to have all counters in each record 
Exactly. This is the goal of the very last paragraph of this email.
If this is not clear, please let me know.

Regards, Benoit.
> as well as
>> A Selector MAY be used in multiple Selection Sequences.  However, 
>> each use of a Selector must be independent, so each separate logical 
>> instance of a Selector MUST maintain its own individual Selection 
>> State and statistics.
>>
>> The Selection Sequence Statistics Report Interpretation MUST include 
>> the number of observed packets (Population Size) and the number of 
>> packets selected (Sample Size) by each instance of its Primitive 
>> Selectors.
>> Within a Selection Sequence composed of several Primitive Selectors, 
>> the number of packets selected for one Selector is equal to the 
>> number of packets observed by the next Selector.  The order of the 
>> Selectors in the Selection Sequence Statistics
>> For every Selection Sequence, the PSAMP Device MUST periodically 
>> export a Selection Sequence Statistics Report Interpretation using an 
>> Options Template containing the following Information Elements:
>> packetsSelected Information Element [PSAMP-INFO]
>> The Attained Selection Fraction for the Selection Sequence is 
>> calculated by dividing the number of observed packets 
>> (packetsObserved Information Element) by the value of selected 
>> packets (packetsSelected Information Element) for the last Selector.  
>> The
>> Attained Selection Fraction can be calculated for each Selector by 
>> dividing the number of packets selected for that Selector by the 
>> value for the previous Selector.
>>
>> and other encapsulation headers) and some subsequent bytes of the 
>> packet payload.  Alternatively, the number of
>> contiguous bytes may start at the beginning of the payload. The 
>> dataLinkFrameSection, mplsLabelStackSection, 
>> mplsPayloadPacketSection, ipPacketSection, and ipPayloadPacketSection 
>> PSAMP Information Elements are available for this use.
>>
>> In the Packet Report, the PSAMP device MUST be capable of exporting 
>> the number of observed packets and the number of packets selected by 
>> each instance of its Primitive Selectors (as described by the non 
>> scope Information Element of the Selection
>> Sequence Statistics Report Interpretation) although it MAY be a 
>> configurable option not to include them. If exported, the Attained 
>> Selection Fraction may be calculated precisely for the Observed 
>> Packet Stream. The Packet Report MAY include only the
>> final selector packetSelected, to act as an index for that selection 
>> sequence in the Selection Sequence Statistics Report Interpretation, 
>> which also allows the calculation of the Attained Selection Fraction.
>>