All things related to multicast

["Lucy E. Lynch" <>]

Gentlemen -

A little Abilene/multicast related puzzle which has been confusing me for
weeks - Purdue has a regular session up from their VIPER lab - but I get
irregular behavior both from the announcement in SDR and the sessions
themselves -

If I can see the announcement, I can join both audio & video, and once I'm
joined I'll stay joined till I shut down my clients - and sometimes I can
join the video even if the announcement isn't visable - but not the audio. 
(The sessions will show up in SDR-monitor as reachable for other folks,
but not for me). This "twinkle" effect is intermittant, although Gregory
Cook assures me that his session is persistant.

A traceroute to the source address goes via Abilene, but mtrace goes via
ALTERNET. I assume this is the commodity route for Purdue. Why is 
multicast traffic between Abilene connected sites going out this
route? Why does it break both SDR announcements and direct connections?
Why does it only break some of the time? I'm damned if I can figure out
why "sometimes the magic works amd sometimes it doesn't" 

Current info:

traceroute 128.46.200.203
traceroute to 128.46.200.203 (128.46.200.203), 30 hops max, 40 byte packets
 1  cisco3-gw.uoregon.edu (128.223.214.1)  1.949 ms  1.927 ms  1.316 ms
 2  cisco7-gw.uoregon.edu (128.223.2.7)  1.377 ms  1.361 ms  1.396 ms
 3  ogig-uo.oregon-gigapop.net (198.32.163.1)  1.389 ms  1.306 ms  1.274  ms
 4  den.oregon-gigapop.net (198.32.163.14)  34.739 ms  32.896 ms  32.860 ms
 5  kscy-denv.abilene.ucaid.edu (198.32.8.14)  54.659 ms  44.750 ms 44.381 ms
 6  ipls-kscy.abilene.ucaid.edu (198.32.8.6)  52.702 ms  52.528 ms  52.526 ms
 7  cisco-tel-ab.tcom.purdue.edu (192.5.40.9)  57.620 ms  57.733 ms 57.457 ms
 8  new-cisco1-252.tcom.purdue.edu (128.210.252.5)  59.112 ms  58.599 ms 
59.769 ms
 9  viper2.ecn.purdue.edu (128.46.200.203)  58.654 ms *  59.047 ms

n=2150549707 2150549707 952454704 224.2.127.254 9875 127 trusted none none 
noauth noenc notset notset 
k=
v=0
o=gcook 3161002987 3161003081 IN IP4 viper2.ecn.purdue.edu
s=VIPER Lab Continuous Streaming Test
i=A continous live video feed for testing purposes.  Video data is copyright 
TV-18, Lafayette, Indidana.
u=http://stargate.ecn.purdue.edu/~ips
e=Gregory W. Cook (Purdue University) 
<>
p=Gregory W. Cook (Purdue University) +1 765 494 3645
t=3160987200 3163449600
r=1d 12h 0
a=tool:sdr v2.8
a=type:test
m=audio 20282 RTP/AVP 0
c=IN IP4 224.2.164.161/127
a=ptime:40
m=video 63518 RTP/AVP 31
c=IN IP4 224.2.252.195/127

Mtrace from 128.46.200.203 to 128.223.214.23 via group 224.2.164.161
Querying full reverse path... 
  0  pythia.uoregon.edu (128.223.214.23)
 -1  cisco3-gw.uoregon.edu (128.223.214.1)  PIM  thresh^ 0   [default]
 -2  cisco7-gw.uoregon.edu (128.223.2.7)  Unknown protocol code 8  thresh^ 0  
Unknown error code 8 [128.46/16]
 -3  Tunnel21.mb1.EWR1.ALTER.NET (137.39.26.97)  Unknown protocol code 8 
thresh^ 32  Unknown error code 8 [128.46/16]
 -4  Loopback0.MB1.BOS1.ALTER.NET (137.39.3.65)  Unknown protocol code 6 
thresh^ 0   [128.46/16]
 -5  cisco-tel-252.tcom.purdue.edu (157.130.101.106)  PIM  thresh^ 32 Unknown 
error code 8 [128.46.200/24]
 -6  new-cisco1-252.tcom.purdue.edu (128.210.252.5)  PIM  thresh^ 0 
[128.46.200/24]
 -7  viper2.ecn.purdue.edu (128.46.200.203)
Round trip time 589 ms

Mtrace from 128.223.214.23 to 128.46.200.203 via group 224.2.164.161
Querying full reverse path... 
  0  viper2.ecn.purdue.edu (128.46.200.203)
 -1  new-cisco1-252.tcom.purdue.edu (128.210.252.5)  PIM  thresh^ 0 [default]
 -2  cisco-tel-252.tcom.purdue.edu (128.210.252.22)  Unknown protocol code 5  
thresh^ 0  Unknown error code 8 [default]
 -3  Loopback0.MB1.BOS1.ALTER.NET (137.39.3.65)  Unknown protocol code 8 
thresh^ 32   [128.223/16]
 -4  Loopback0.MB1.EWR1.ALTER.NET (137.39.3.92)  Unknown protocol code 8 
thresh^ 0  Unknown error code 8 [128.223/16]
 -5  MBGP-UO.Mbone.ALTER.NET (137.39.26.98)  PIM  thresh^ 32  Unknown error 
code 8 [128.223.214/23]
 -6  cisco3-gw.uoregon.edu (128.223.2.3)  PIM  thresh^ 0 [128.223.214/23]
 -7  pythia.uoregon.edu (128.223.214.23)
Round trip time 728 ms

Any clues you can share...

Lucy E. Lynch                           Academic User Services
Computing Center                        University of Oregon

                (541) 346-1774
Cell: (541) 915-4189                    

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