[e2e] TCP, retransmissions, and ISPs with byte caps

[Philippe Strauss]

Hello Simon!

On Wed, Jun 19, 2002 at 01:30:07AM +0200, Simon Leinen wrote:
> >>>>> On Tue, 18 Jun 2002 08:57:18 -0400, "David P. Reed" <dpreed at reed.com> said:
> > At 08:17 AM 6/18/2002 +0200, Philippe Strauss wrote:
> >> But about delays, CATV systems have an interesting characeristic:
> >> a ~20ms minimum delay in the ACK path (direction from home
> >> to the hub, upstream or return path in catv speak).
> [...]
> > Perhaps you meant 20 *micro* seconds?
> 
> > Or maybe Swiss cable systems are really really slow.
> 
> Hm, I'm using what is probably the prevalent Cable ISP in Switzerland
> (Cablecom).  I think they are using DOCSIS 1.1, my cable "modem" is a
> Cisco CVA-122(E?).  The results are quite similar to yours
> (when I replace MIT by its Swiss counterpart :-).
> 
> : leinen at diotima[leinen]; mtr -r www.ethz.ch
> HOST                                    LOSS  RCVD SENT    BEST     AVG   WORST
> 10.224.96.1                               0%    16   16    5.93    8.02   16.93
> 62.2.24.221                               0%    16   16    5.67    6.81    9.16
> 62.2.6.34                                 0%    16   16    6.59    8.00   11.82
> switix-f1-0.switch.ch                     0%    16   16    6.85    8.66   13.24
> swiEZ2-G3-2.switch.ch                     0%    16   16    7.15    8.35   10.12
> rou-eth-switch-1-giga-to-switch.ethz.ch   0%    16   16    7.11    8.51   11.06
> rou-rz-1-mega-transit.ethz.ch             0%    16   16    7.19    8.59   11.57
> w3.ethz.ch                                0%    16   16    6.79    8.33   12.72

here's an equivalent for me, with the terayon teracom 1000:

                           Matt's traceroute  [v0.51]
philou.ch                                              Wed Jun 19 13:27:12 2002
                                           Packets               Pings
Hostname                                %Loss  Rcv  Snt  Last Best  Avg  Worst
 1. TeraGWatm-Bussigny.Urba.Net            0%   41   41    26   23   26     57
 2. Bussigny-e00.Urba.net                  0%   41   41    27   24   28     36
 3. Lsne4-B2-fe0-0.urba.net                0%   41   41    26   24   28     80
 4. 62.2.6.177                             0%   41   41    28   24   58    395
 5. 62.2.4.190                             0%   41   41    30   29   31     35
 6. switix-f1-0.switch.ch                  0%   41   41    29   29   54    442
 7. swiEZ2-G3-2.switch.ch                  0%   41   41    34   29   34     46
 8. swiCE2-G2-2.switch.ch                  0%   41   41    33   30   36     92
 9. swiCE1-G0-0-0.switch.ch                0%   41   41    30   29   33     36
10. swiGEX-A0-0-0-9.switch.ch              3%   40   41    35   31   39    209
11. swiEL1-A4-0-0-1.switch.ch              0%   41   41    38   33   52    365
12. 192.33.208.1                           3%   40   41    34   32   37     41
13. ro-ma-v100.epfl.ch                     0%   41   41    36   33   38    100
14. empc22.epfl.ch                         0%   40   40    34   33   37     51


cheers.

-- 
Philippe Strauss
http://philou.ch/

L'indifférence est le plus grand risque de notre temps,
la forme civilisée de la cruauté.  -- Zenta Maurina
--