Re: [sfc] Figures in draft-quinn-sfc-arch-05

[Eric Gray <[e-mail]>]

Linda/Lucy,

                It's not a beauty contest.  There are trade-offs associated with using
any of these approaches.

                If the authors decide to use Lucy's approach, they will need to add a
little bit more text to explain the notation (sf1|sf1' meaning two separate
nodes providing the same service function, where packets may be processed
by either) - as it is not as intuitive as if separate boxes are used in the figure.

                Your suggestion would require even more additional text, as it is (in
effect) applying the same sort of notation recursively - especially if applied
to both figures 5 and 6.

                Either approach would be fine with me, provided the text to make
it clear what these figures mean is provided.

                For other folks - particularly those who understand things better if
they are clearly explained pictorially - having the need to add extra text to
make the picture itself more understandable may not work that well.

                I'm personally fine with any of the options discussed so far, and am
perfectly happy to let the Editors of the draft make whatever choice they
prefer, for whatever reasons they prefer that (or those) choice(s).

--
Eric

From: Linda Dunbar [mailto:[e-mail]]
Sent: Thursday, May 29, 2014 4:49 PM
To: Lucy yong; Eric Gray; Jakob Heitz (jheitz); Joel Halpern; Paul Quinn (paulq)
Cc: [e-mail]
Subject: RE: Figures in draft-quinn-sfc-arch-05
Importance: High

I like the Figures drawn by Lucy.

Actually why can't Figure 5 be simplified as

    enter -->{sf1}-->-{sf2|sf2'|sf2''}->--{sf3}-->-{sf4|sf4'|sf4''}->--{sf5}--> exit

??

Linda

From: sfc [mailto:[e-mail]] On Behalf Of Lucy yong
Sent: Thursday, May 29, 2014 1:12 PM
To: Eric Gray; Jakob Heitz (jheitz); Joel Halpern; Paul Quinn (paulq)
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [sfc] Figures in draft-quinn-sfc-arch-05

For readability on these figures, propose:

Figure 5:
                     +-sf2-+       +-sf4-+
                     |     |       |     |
       enter -->sf1-->-sf2->--sf3-->-sf4->--sf5--> exit
                     |     |       |     |
                     +-sf2-+       +-sf4-+
Figure 6:

                         +-sf2-+              +-sf4-+
                         |     |              |     |
    enter -->{sf1|sf1'}-->-sf2->--{sf3|sf3'}-->-sf4->--{sf5}--> exit
                         |     |              |     |
                         +-sf2-+              +-sf4-+

lucy
From: sfc [mailto:[e-mail]] On Behalf Of Eric Gray
Sent: Thursday, May 29, 2014 12:54 PM
To: Jakob Heitz (jheitz); Joel Halpern; Paul Quinn (paulq)
Cc: [e-mail]<mailto:[e-mail]>
Subject: Re: [sfc] Figures in draft-quinn-sfc-arch-05

HaHa, funny man.  :)

From: Jakob Heitz (jheitz) [mailto:[e-mail]]
Sent: Thursday, May 29, 2014 1:43 PM
To: Eric Gray; Joel Halpern; Paul Quinn (paulq)
Cc: [e-mail]<mailto:[e-mail]>
Subject: RE: Figures in draft-quinn-sfc-arch-05
Importance: High

You could turn the whole picture right by 90 degrees.
If you don't like top to bottom instead of left to right, make a note that it's in landscape.

--Jakob

From: sfc [mailto:[e-mail]] On Behalf Of Eric Gray
Sent: Thursday, May 29, 2014 8:31 AM
To: Joel Halpern; Paul Quinn (paulq)
Cc: [e-mail]<mailto:[e-mail]>
Subject: [sfc] Figures in draft-quinn-sfc-arch-05

Paul/Joel,

                Pretty sure that Figures 5 and 6 don't actually fit the width expected for an
Internet Draft (Figure 5 is more than 80 characters wide and Figure 6 is wider still).

                Depending on how a reader tries to read the draft, this can turn complicated
illustrations into a _real_ fun time.  :)

                Also, I am unsure what the figures are trying to convey with some of "dotted
lines" crossing the service functions.  If the intent is to show that a service function is
a virtual instance hosted by some network device, perhaps this will be better shown
in a separate figure and this aspect of Figures 5 and 6 can be eliminated?

I would suggest replacing Figure 5 with a figure along the lines of:

source             +-----+                   +-----+
  |            +-->| sf2 +--+            +-->| sf4 +--+
  |            |   |     |  |            |   |     |  |
  |  +------+--+   +-----+  +-->+-----+--+   +-----+  +->+-----+
  |  | sf1  |      +-----+      | sf3 |      +-----+     | sf5 |
  +->|      +----->| sf2 +----->|     |----->| sf4 +---->|     |-+
     |      |      |     |      |     |      |     |     |     | |
     +------+--+   +-----+  +-->+-----+--+   +-----+  +->+-----+ |
               |   +-----+  |            |   +-----+  |          |
               +-->| sf2 +--+            +-->| sf4 +--+     +----+
                   |     |                   |     |        |
                   +-----+                   +-----+        V
                                                          destination

                   Figure 5: Load Balancing

(67 characters?)

                Similarly, I would suggest replacing Figure 6 with a figure along the
lines of:


   source

     |               +-----+-+                   +-----+-+

 +---+           +-->| sf2 |-|+              +-->| sf4 |-|+

 |           +---|-->|     | ||          +------>|     | ||

 |   +------+|---+   +-----+ |+-->+-----+|---+   +-----+ |+-->+-----+

 |   | sf1  ||       +-----+ +--->| sf3 ||       +-----+ +--->| sf5 |

 +-->|      +|------>| sf2 |+---->|     ||------>| sf4 |+---->|     |--+

 |   |      || +---->|     |-+    |     || +---->|     |-+    |     |  |

 |   +------+|-|-+   +-----+ |+-->+-----+|-|-+   +-----+ |+-->+-----+  |

 |           | | |   +-----+ ||          | | |   +-----+ ||            |

 |   +------++ | +-->| sf2 |-|+   +-----++ | +-->| sf4 |-|+   +-----+  |

 |   | sf1' |  | +-->|     | +--->| sf3'|  | +-->|     | +--->| sf5'|  |

 +-->|      +--+ |   +-----+----->|     |--+ |   +-----+----->|     |--+

     |      |    |                |     |    |                |     |  |

     +------+----+                +-----+----+                +-----+  |

                                                                       |

                                                              +--------+

                                                              |

                                                              V

                                                         destination



                    Figure 6: Load Balancing and HA

(72 characters?)

                In both cases, the figure has all the same connection complexity (fixed up in a few
places), but seems to be less busy.

--
Eric