Subject: [trill] Shepherds review of draft-directory-assist-mechanisms

From: "Susan Hares" <[email-masked]>
Date: Fri, 2 Oct 2015 15:46:42 -0400

This is a shepherd’s review for: 

http://datatracker.ietf.org/doc/draft-ietf-trill-directory-assist-mechanisms
/

Shepherd’s review: 

Status:  Technically sound, but needs minor technical editing done before
sending to IESG.

One thing the authors need to consider is whether all the knobs specified in
the draft are documented carefully.

The shepherd believes at least 5 knobs were not document.  

Minor Technical: (needs clarifying before goes to IESG). 

#1 - Section 2.2.3 text: 

The activate condition in sentence: 

“For example, the Push Directory server is configured that 2 copies should b
epushed and finds that it is priority 1 or 2 among the Push Directory
servers it can see.” 

Note: “can see” does not correctly specify what is happening.  I suspect
that the appropriate response is “Push Director servers is receiving
messages from”.  However, the paragraph needs the technical clarification. 

#2 - Section 2.4 – 

Additional Push details needs revising if the APPsub-TLV is revised. 

#3 – Section 3.2.2.1 

Text: “Response are sent with the same Data Label and priority as the Query
Message to which they correspond except that the Response Message priority
is limited to be not more than a configurable value”.

Comment: It would be good to have a set of values which specify what the
configured value is.  Is this a max-message-response query?  If so, we need
a place to collect these timers if there are not being specified in the
section.  If it is being specified in the section, then I missed it.  Help
me by specify what the configured value is. 

#4 – top of page 25 starting with the text “A Pull Directory server” – You
need to specify the knob 

Textual suggestions toward the knob 

//it has sent an Update message and received a corresponding Acknowledge
Message or tit hs sent a configurable number of updates at configurable
interval which default to 3 updates with 100 milliseconds apart/ 

To 

 /it has either: a) sent an Update message and received a corresponding
Acknowledge Message, or b) it has sent a configurable number of updates at a
configurable rate (set by [knob name]).   The [knob name] defaults to a
setting of 3 updates 100 milliseconds apart. / 

#5 – page 34 –

It is not clear why the If Flooded Immediately goes from 2 à 0 à 1 à 1

Please add something that helps me understand this. Or tell me why I’m crazy
to think this. 

#6 – IANA  - Has OK the IANA section 

======================

Editorial: 

#1 Section: 2.2, p. 7 paragraph 2 

p. 7 – good to reference in paragraph 3 beginning “For each Data label it
can serve” the section 2.3 below. 

#2 Section 2.2.3 text: 

The activate condition in sentence: 

“For example, the Push Directory server is configured that 2 copies should b
epushed and finds that it is priority 1 or 2 among the Push Directory
servers it can see.” 

#3 Section 3.2.1 – Pull Directory Query Message Format

Page 18: Query address – you give MAC address and IP address as examples.
If you have some other time of address, we should really have an example.
In fact it would be useful to have examples to improve the technical
clarity.   

p. 18 – paragraph at bottom of page

/If no response is received to a Pull Directory Query Message within a
timeout configurable in milliseconds that default to 100, the query message
should be re-transmitted within the same Sequence Number up to a
configurable number of times that defaults to three. / 

 To 

/If no response is received to a Pull Directory Query Message within a
pull-query timeout period, then the query message should be re-transmitted
with the same sequence number (up to pull-query-retransmit-limit). The
pull-query timeout is a configurable knob that defaults to 100 ms.  The pull
query retransmit-limit is a configurable knob which defaults to three. 

#4 spelling on page 21 – top of page 

/“message level error code in it, then the the REPONSE” / 

To /  “message level error code in it, then the RESPONSE

Change /ecosing/ enclosing/

Change: /Repose/ Response/ 

IN the next paragraph: /Multiple RESPONSE Records can appear in a Response
Message with the same Index if the answer to a QUERY Record/

To 

/Multiple RESPONSE Records can appear in a Response Message with the same
Index if the message is an answer to the QUERY Recrord/

#4 section 3.2.2.2 Pull Directory Forwarding 

Second sentence of paragraph: 

/In these cases, if the information is not in the directory the provided
frame is forwarded by the Pull Directory server as a multi-destination TRILL
Data packet if the FL Flag in the Query message was one./

To 

/In these cases, if the information sought is not in the directory and the
FL flag in the query message was one, the provided frame is forwarded by the
Pull Directory server as a multi-destination TRILL Data packet. / 

 #5 – section 3.2.2.2 

Location: MacDA: 

/fame/frame

#6 – 3.3. cache consistency

In the second paragraph, I would recommend that you break after the first
sentence and provide the text at the top of page 23. 

Here’s the example: 

A Pull Directory server MUST maintain one of the following three sets of
records in order of increasing specificity: 

1)      Retaining more specific records such as given in method 3 below,

2)      Retaining less specific records such as given in method 1 below, 

3)      ????

Method 1: (include text) 

                Pro: Put the pro/con by the method from above

            Con:  

Method 2: (Include text) 

                Pro:

            Con: 

Method 3:  ((including text) 

                Pro:

                Con: 

Put the pro/con by the method. 

Pull Directory issues: 

Include the pull directory test (p. 23-24) 

#7 – page 23 

Bottom:  If method 1 (the crudest method) 

Suggestion: find another word or phrase beside “cruide”  

#8 – page 24 – top 

Paragraph beginning “If method 2 is being followed: 

Delete /Such message are somewhat similar to the method 1 flooded flush
update and are also sent a RBridge Channel messags with an ..” 

Either break into two sentences or delete “such messages are someone
similar” or provide more details.

#9  - page 24 bottom 

/unsolicited response are compared to the addresses about which/

/unsolicited responses are compared to the addresses which/ 

#10 – section for 2a, 2b. 2c., 2d in section 3.3 

                Suggest you use a format of: 

Situation: Description of situation  

Action: Action occurring in the step 

#11 – 3.3.1 Update format 

/Update messages are initiated by a Pull Directory Server.  The Sequence
number space is controlled by the original Pull Directory server, [1] and
different from Sequence number spaced used in a Query and the corresponding
Response that are controlled by the querying TRILL switch./ 

At [1] suggest you end the sentence /Pull Directory server. This [name]
Sequence number space  is different than from the Sequence number. 

Otherwise it is a bit confusing. 

#12 – 3.3.2 Acknowledge Message format (p. 26) 

Paragraph 1 

/It is also formatted as a Response Message but the Type is set to 4. /

/It is formatted as a Response Message but the Type is set to 4./

#13 /paragraph 2/ 

Remove /essentially/ - it seems to server purposes. 

#13 Section 3.5 Pull Directory Hosted on an End Station.  (p., 27) 

This section could really clarified by adding a picture.. 

#14 – Section 3.5 page 28 

Nickname section

From: 

/The proxy copies this from the ingress nickname when mapping a Query or
Acknowledge Message to a native form.  It also takes this from a native
Response Message or a Update Message to be used/

To: 

/The proxy copies this nickname from the ingress nickname when mapping a
Query or Acknowledge Message to a native form.  It also takes this nickname
from a native Response Message or a Update Message to be used/

#15 – section 3.5. p. 28 section Data Label

From: /RBridge Channel Pull Directory messages appears here/ 

To  /RBridge Channel Pull Directoy Messages appears in this field/

From: /This might appear/

To: This database might appear/ 

#16 page 29 section 3.6 paragraph top of page 

/probably were not even looked at by the Pull Directory server and would
provide no information in the Response or Acknowledge Message so they are
omitted and the Count field is set to zero in the Response or
Acknowledgement Message./

/probably were not even looked at by the Pull Directory Server and would
provide no additional information in the Response or Acknowledge Message.
Therefore, this section with the Query Response or Update Message or header
is omitted and the Count field is set to zero in the Response or
Acknowledgement Message/.

p. 29.  Paragraph 2/3 – “a Acknowledge Message/ an Acknowledge message/ 

#17 – section 3.8 

>From /But, with the Push and Pull/

To: /However with the Push and Pull/

From: /It may cause increased link utilization/

To: /It may cause increased link utilization due to traffic/ 

Note: If this is not correct, then the text needs to be improved in this
paragraph.