Re: [vmeet] Experience as a remote attendee

[Simon Pietro Romano <[e-mail]>]

Hello Dan,

I hope I can add some more bits to this discussion. 
I was remote this time and I seized this as an opportunity to live the Meetecho experience  from the other side for once! 
I have been attending a bunch of sessions, both from my university office and from home (overnight sessions in Italy due to the 5-hours time shift). At the university I have a high-bandwidth connection, which allowed me to easily open up to 8 Meetecho virtual rooms in parallel with no issue. At home I connect through WiFi to my home gateway, from which I have an ADSL (Asymmetric DSL, which means I have around 4 Mbit/sec downlink and less than 1 Mbit/sec uplink to the Internet backbone). Such a link allowed me to reliably attend at most a couple of parallel sessions. With more than that, I could experience hiccups from time to time, which is as expected, given the fact that each session involves two video streams (each of which accounts for about 400 Kbit/sec on average), plus an audio stream (let’s say about 150 Kbit/sec or so). In case of remote presentations, each remotee obviously adds one further video stream to the pack. If you add to that the lower- bandwidth Meetecho traffic (chat, client-server polling and the like), plus some background traffic not generated by Meetecho, you easily arrive at (or close to) saturation. I can also confirm that the  internal WiFi connection to the ADSL router concurs in reducing the reliability level of real-time streaming (which by the way occurs to me also when I watch a Netflix movie with my family). A wired connection to the router definitely makes the life of a real-time session much easier.
All in all, I can confirm that attending a single session can be considered, from my personal experience, close to 100% reliable in the above described conditions.

As a final remark, I would like to highlight the fact that the connection from BA to Italy was showing a really weird behavior in terms of network performance as a function of the time of the day. And this is something I have not been able to fully understand (even though I teach an Advanced Computer Networks class since 1998 ;-) ). I am still investigating this, by looking at things like BGP route flapping, time-dependent traffic shaping policies — at the firewall level — on the Italian Research backbone and/or at the ingress router of my University campus network, etc.. 

To give you an idea of what I am talking about, I’ll provide you with some side information:

- we record all Meetecho sessions on-site (i.e., this time, in BA);
- at the end of each slot (lunch break and end of the day) we transfer, via scp (secure copy command) all recorded files to a backend server hosted in Italy;
- the lunch-time transfers happened at an average speed of more than 4MB/sec;
- evening (in BA, which means night time in Italy) transfers happened at less than 50KB/sec, which is astonishingly less than the other figure above;
- a basic “ping” from BA to Italy resulted in around 300 msec estimated round-trip time during day and more than 500 msec at nights.

Now, coming to one of your comments:

> I wonder if there was an increase in usage during the week, either of Meetecho or also of the IETF network.  We may be able to find out from the Meetecho or NOC team.

As far as Meetecho is concerned, the load has been quite stable over the week. Monday has, by the way, represented a peak for what concerns remote presentations (more than 25 of them, if I recall correctly).

Hope this helps,

Simon

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                    				Simon Pietro Romano
             				 Universita' di Napoli Federico II
                		     Computer Engineering Department 
	             Phone: [phone] -- Fax: [phone]
                                           e-mail: [e-mail]

		    <<Molti mi dicono che lo scoraggiamento è l'alibi degli 
		    idioti. Ci rifletto un istante; e mi scoraggio>>. Magritte.
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