- Test - lists.nanog.org

SSM vs MSDP (was: IP Multicasting)
by Bill Nickless 04 Jan '01

04 Jan '01

-----BEGIN PGP SIGNED MESSAGE----- Jared Mauch writes: >The advent of SSM (single source multicast) makes such one-to-many much >easier than in the past. I would be interested in learning more details about how this is the case, operationally, today. My perspective argues against Jared's statement as I understand it. For the past 18 months or so I've been involved in making IP multicast work for the Access Grid project (see http://www.mcs.anl.gov/accessgrid ) which is admittedly a many-to-many application. Since the Access Grid project started we have been able to use it to run several multi-day meetings with roughly a dozen sites, plus literally hundreds of meetings with 2-5 sites. We have seen the larger meetings consume 20 megabits/second of multicast bandwidth, sustained for 10+ hours over 2-3 days. Few sites could afford the N^2 bandwidth requirement of unicast, so Access Grid is fundamentally dependant on IP multicast to work properly. I've had lots of fun debugging IP multicast deployment over the past 1.5 years. This has been at sites ranging from national laboratories to universities to Native American tribal colleges, in cooperation with the folks at networks like vBNS+, Abilene, and ESNet and their various connectors. SSM introduces new things to debug, and I think makes IP multicast deployment harder to actually deploy than the existing M-BGP/PIM-SM/MSDP model. Please note the date on this message--these comments are likely to be obsolete in the future. But for now, here are three major reasons why: No SSM Support in IP Multicast Beacon Tool ========================================== We developed a Java-based tool to monitor IP multicast reachability. This tool is intended to be deployed on end stations. Each end station reports reachability to a central server, which makes the information available on a web page (see http://beaconserver.accessgrid.org:9999 for the reachability matrix, and http://dast.nlanr.net/projects/beacon for the code itself.) Obviously this tool could be updated to support SSM, but it's not there yet. SSM Requires IGMPv3 Or Other Proprietary Hacks At The End Station ================================================================= Implementing SSM is trivial at the service provider. Once you have M-BGP and PIM Sparse Mode working you are pretty much done, since your customers will have the burden of sending you PIM-SM joins. It's even easier, because you don't have to worry about MSDP. But at the customer things are much harder. First, the customer has to provide SSM/IGMPv3 support at the edge network devices, and that support is by no means widespread. Second, the customer has to install and debug the IGMPv3 support in the end stations, which is just now becoming available. Compare IGMPv3 availability with IGMPv2 for Windows 95. And finally the middleware and applications need to be appropriately coded to handle the SSM/IGMPv3 model. Are the major Java distributions supporting IGMPv3 yet? What about ACE? (See above for IP Multicast Beacon tool; it's pure Java.) MSDP As A Useful Debugging Tool =============================== Yes, MSDP is another protocol you have to configure and maintain as a service provider. But I have found it to be useful debugging tool for confirming proper operation of M-BGP and PIM-SM in certain cases. - Customer site without PIM-SM configured properly on a sender. If the customer isn't generating an MSDP SA, then we can quickly point the finger at the customer, and give the customer a specific thing to get working (the MSDP advertisements, a.k.a. the A flag on new-model Cisco code.) - Customer site not properly doing route path forward calculation, due (possibly) to misconfiguration of M-BGP. This shows up as MSDP SAs not being properly accepted in the customer. That explains why a customer might not be sending PIM-SM joins towards the service provider. In both of these cases, trying to debug without MSDP, but with SSM, would require considerably more debugging effort. One would need to go deeper into the customer network and/or turn on PIM-SM debugging at the customer edge. Summary ======= If your objective is to reduce the amount of work your engineering staff has to do to support IP Multicast, I can guarantee that telling your customers to use M-BGP/PIM-SM/SSM instead of M-BGP/PIM-SM/MSDP will help a lot--but (in my opinion) for the wrong reason: it will delay the actual availability of IP Multicast service to the end user. Telling your customers to use M-BGP/PIM-SM/SSM *IN ADDITION TO* M-BGP/PIM-SM/MSDP will indeed help reduce the amount of global MSDP state carried in routers over the long term, and that's arguably a very good thing. I look forward to ubiquitous support of IGMPv3 in lots of vendors products--whether they be layer 2, layer 3, software, or whatever. === Bill Nickless http://www.mcs.anl.gov/people/nickless +1 630 252 7390 PGP:0E 0F 16 80 C5 B1 69 52 E1 44 1A A5 0E 1B 74 F7 nickless(a)mcs.anl.gov -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.8 for non-commercial use <http://www.pgp.com> iQCVAwUBOlJN+awgm7ipJDXBAQEQpQQAh2JkINd3K0ZTc3gM+xl2U1luyTufDDqq Kk5AMEIfAi57kXGTmMSnSOfVolTMiz/BLHROKq0BR4q+pZuIWHuaWdUcek4vkPBM FubhTpAUqFVvS4XKgwQkJFOEHw70hK0h2r7kmTilmNSI8MaPYzm6A992e/dM8apP BojosYEvoRs= =prQv -----END PGP SIGNATURE-----

4 5

Re: SSM vs MSDP (was: IP Multicasting)
by brandon＠rd.bbc.co.uk 04 Jan '01

04 Jan '01

> Without sap/sdr capabilities, SSM will never take off. I don't see why, nice to have but not required for it's likely market - replacing unicast streaming media > Having all the web pages out there are nice extras, but do not > replace the needed builtin tools. For the users web works fine at the moment and some content providors would prefer people to look at the pages as well as the stream Doesn't mean it wouldn't be nice to have it as well though some portals would hope not or wish to own it. brandon

1 0

Further Internet Metrics
by Eric Lemond 03 Jan '01

03 Jan '01

The Internet Metrics post in December was a good starting point for my research on backbone traffic, but I'm struggling to get more specific information. Specifically, I am trying to find out the market share for the major backbone providers (so far I've found WorldCom 37% and Sprint 16% of traffic). Boardwatch has this breakdown, but by ISP connections (WorldCom 24% & Sprint 14%). Is the percent of ISP connections a good estimate of the percent of traffic a backbone carries? Also, for the major backbones, is there any kind of breakdown of the percent of a backbone's traffic that is for a corporate end user vs. a personal dial-up or broadband account. Specifically, does WorldCom, Sprint, C&W, ATT, Genuity, Level 3's traffic have a strong tendency to be for corporate or personal accounts? Finally, Is there any source or estimate for the current total amount of Internet traffic carried by all networks? Any information or sources would be greatly appreciated. Thanks, Eric ---------------- Eric Lemond Interdiciplinary Telecommunications Program, CU Boulder Intern, FastIdeas

5 5

RE: Dialup congestion and winter weather (fwd)
by Roeland Meyer 03 Jan '01

03 Jan '01

That isn't the only issue. I've just found that Southern Bell does bandwidth limiting on their residential customers. Most folks would never know the difference, but when v.90 modems start consistantly connecting at 14.4K, or less, then I know that the telco is only allowing 32K per voice channel (rather than the usual 64K). BTW, that was using AT&T universal LD from Graham, NC, to Livermore, CA. I only ever got full-speed late at night. > -----Original Message----- > From: multics(a)ruserved.com [mailto:multics@ruserved.com] > Sent: Wednesday, December 27, 2000 8:47 PM > To: nanog(a)merit.edu > Cc: multics(a)ruserved.com > Subject: Dialup congestion and winter weather (fwd) > > > > An important question to ask people reporting this type of > problem is > are they getitng a normal busy (all modems busy) or a fast busy (telco > out of circuits). Two very different problems. An ISP can work on > fixing the first, but the second is a telco with a shortage > of circuits > between the customer and the isp. > > > It seems like a lot of people are at home, dialing into the Internet > > today. There is a major ice storm in the middle of the country, and > > its pretty much a holiday week elsewhere. Traffic seems to > be moving on > > the major backbones, but some folks in the midwest report > some problems > > dialing in from home. > > -- > Richard Shetron multics(a)ruserved.com multics(a)acm.rpi.edu NO UCE > What is the Meaning of Life? There is no meaning, > It's just a consequence of complex carbon based chemistry; > don't worry about it > The Super 76, "Free Aspirin and Tender Sympathy", Las Vegas Strip. >

1 0

@Home peering contact?
by Alex 03 Jan '01

03 Jan '01

I've tried to get in touch with peering(a)home.com; I've tried to leave that individual an vmail, and I get a 'mailbox is full, goodbye'; I've sent an email to him, and I've no response. Does anyone know of a working peering contact over there? Or, and @home lurkers here? Thanks!

1 0

ARIN Person...
by dies＠pulltheplug.com 02 Jan '01

02 Jan '01

Could someone from ARIN gimme an email off list? I wasn't paying attention to the /20 discussion so I never got a name. Thanks!

1 0

Globally unique versus globally routable (was RE: RFC1918)
by Sean Donelan 02 Jan '01

02 Jan '01

> Using RFC1918 space also gets you an IP range where the outside world has > no route to it -- Sorry, but no packets are not getting there, ergo no way > to hack. > > At that point, just by use of simple routing, you've effectively > eliminated 100% of attacks from the outside, and you only have to worry > about inside. The front door is secure, now work on the back door. One of the things which has always annoyed me about this argument was people making the assumption that routing of addresses and registration of addresses was related. You can have a globally unique address, registered with an address registry (arin, ripe, apnic), which is not routed on the Internet. You can have a "private" shared address, which is routed on the Internet. People who can't figure out how to filter, also can't figure out how to filter RFC1918 addresses. So route leaks of RFC1918 space are common. If your filters are properly configured, there is no difference in the security of RFC1918 addresses or globally unique addresses. What makes RFC1918 addresses "secure" isn't the addresses, but the route filters. If your filters aren't properly configured, there is no difference in the security of globally unique addresses or RFC1918 addresses. Personally, I prefer to always use globally unique addresses whether or not they are announced on the Internet because they cause less problems (security, operational, etc) problems when a route does leak. The problem with RFC1918 addresses, is if you an accidental route leak, you have a fairly high probability of getting nailed by someone else using the same address. Humans have an annoying habit of choosing the same "easy to remember" private addresses. If any security consultant tells you your computers are secure because they are using RFC1918 addresses, I would suggest grabbing your wallet and running. And, yes I've heard security consultants from the "Big 5" firms say exactly that. Note: I did not say either RFC1918 addresses or globally unique addresses were secure, only that there is no difference in the level of security between them.

1 0

IP Multicasting
by deen＠slt.lk 02 Jan '01

02 Jan '01

Hello Nanog, We are developing a streaming video based application. Can someone tell me whether (1) Multicasting is necessary for such an application (2) How do we configure multicasting, and multicast (224.x.x.x) to Global IP Conversion, on Cisco Routers. Some useful sites will be handy. (3) What is the function of the MBone network, and whether it is required for such a situation. Deen Sri Lanka Telecom Internet

6 7

Re: IP Multicasting
by Kevin Facinelli 02 Jan '01

02 Jan '01

Eric, Your research sounds very interesting. As to your question I have come across a few sites that you may want to take a look at: 1)http://www.internettrafficreport.com/ 2)http://ratings.miq.net/compare-by-REACHABILITY-Large.html 3)http://www.internethealthreport.com/ These organizations may have what you are looking for or this could be another starting point. Good Luck and keep me posted as to how things are going. Kevin Facinelli webmaster(a)colosource.com www.colosource.com ===== Kevin Facinelli www.colosource.com webmaster(a)colosource.com __________________________________________________ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online! http://photos.yahoo.com/

1 0

Internet metrics III
by jamie rishaw 02 Jan '01

02 Jan '01

Are any major backbones doing Internet metrics in the oldschool (and more interesting) method -- services breakdown? I remember being a cust of OARnet back in the early 90's, being able to look at true metrics.. bandwidth utilization broken down by service, what percentage of bandwidth was being used over what services over a given period of time. I haven't seen anything similar to that in years. I would love to. As would many others, I'm sure. jamie -- i am jamie at arpa dot com .. and this is my .sig. All I want is a kind word, a warm bed and unlimited power. "i remember when i was little, my mom used to tell me how santa couldnt start his journey until all the little boys and girls went to bed around the world... then i remember staying up the whole night just because i thought it would set back christmas for everyone and it would be funny.." - my friend shortie

1 0