Re: Northern Ireland undersea branch to be implemented
On Tue, Jan 6, 2009 at 1:02 AM, Martin List-Petersen mar...@airwire.iewrote: Martin Hannigan wrote: Hibernia has been busy. THE COMMUNICATIONS minister Eamon Ryan and the North's Enterprise Minister Arlene Foster have announced the awarding of a £30 million (€32 million) contract to construct a new direct telecommunications link to North America that will benefit Northern Ireland and the Republic http://www.irishtimes.com/newspaper/finance/2009/0106/1230936699678.html That's just a spur from the existing Hibernia Atlantic fibre that goes from Halifax to Dublin. In my opinion, that should have been done from the very beginning. Is all of this terrestrial network already in place? http://www.hiberniaatlantic.com/maps/HA_NIreland_Routes.pdf -- Martin Hannigan mar...@theicelandguy.com p: +16178216079
? how cisco router handle the out-of-order ICMP echo-reply packets
Hi, Does someone happen to know how the Cisco IOS handle the out-of-order ICMP echo-reply packets? print it as success or lose? Thanks, Zhao Ping
RE: [SPAM-HEADER] - Re: Northern Ireland undersea branch to be implemented - Email has different SMTP TO: and MIME TO: fields in the email addresses
Actually, it is a big deal. Hibernia is already the only cable system that can send Irish traffic directly to North American without backhauling to the UK. That's a significantly latency and diversity advantage. We can now send traffic directly to the US on both cables without UK backhaul and hence provide more physical diversity. It also enables us to serve an underserved market, Northern Ireland, and provide low latency and protected services betweeen the UK and Ireland. And we beat the who-whos of telecom in winning this RFP. :) Regards, Roderick S. Beck Director of European Sales Hibernia Atlantic 13-15, rue Sedaine, 75011 Paris http://www.hiberniaatlantic.com Wireless: 1-212-444-8829. French Landline: 33+1+4355+8224 French Wireless: 33-6-14-33-48-97. AOL Messenger: GlobalBandwidth rod.b...@hiberniaatlantic.com rodb...@erols.com ``Unthinking respect for authority is the greatest enemy of truth.'' Albert Einstein. -Original Message- From: Martin Hannigan [mailto:mar...@theicelandguy.com] Sent: Tue 1/6/2009 11:20 AM To: Martin List-Petersen Cc: nanog@nanog.org Subject: [SPAM-HEADER] - Re: Northern Ireland undersea branch to be implemented - Email has different SMTP TO: and MIME TO: fields in the email addresses On Tue, Jan 6, 2009 at 1:02 AM, Martin List-Petersen mar...@airwire.iewrote: Martin Hannigan wrote: Hibernia has been busy. THE COMMUNICATIONS minister Eamon Ryan and the North's Enterprise Minister Arlene Foster have announced the awarding of a £30 million (?32 million) contract to construct a new direct telecommunications link to North America that will benefit Northern Ireland and the Republic http://www.irishtimes.com/newspaper/finance/2009/0106/1230936699678.html That's just a spur from the existing Hibernia Atlantic fibre that goes from Halifax to Dublin. In my opinion, that should have been done from the very beginning. Is all of this terrestrial network already in place? http://www.hiberniaatlantic.com/maps/HA_NIreland_Routes.pdf -- Martin Hannigan mar...@theicelandguy.com p: +16178216079
Re: ? how cisco router handle the out-of-order ICMP echo-reply packets
Considering that Ciscos wait for a response before sending the next echo-request, you should never end up in a situation where replys are received out of order. That is going by my knowledge of traditional IOS. Ive not yet had any experience with IOS XE or XR to be able to quote any other experience. Tom On 06/01/2009, at 9:56 PM, Zhao Ping wrote: Hi, Does someone happen to know how the Cisco IOS handle the out-of- order ICMP echo-reply packets? print it as success or lose? Thanks, Zhao Ping
Re: question about BGP default routing
Sorry I have question Why it needs default routes when running BGP? Thank you Kai Chen kch...@eecs.northwestern.edu wrote: Will this default route 0.0.0.0/0 be exporting to AS-level neighbors? On Mon, Jan 5, 2009 at 8:49 PM, Edward B. DREGER wrote: KC Date: Mon, 5 Jan 2009 18:05:48 -0600 KC From: Kai Chen KC is this router using a default routing for all the other KC destinations? Either that: router sh ip route 0.0.0.0 Routing entry for 0.0.0.0/0, supernet or partial tables with no default: router sh ip route 0.0.0.0 % Network not in table is what you'd expect. Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter. - Ask a question on any topic and get answers from real people. Go to Yahoo! Answers. - Yahoo! Canada Toolbar : Search from anywhere on the web and bookmark your favourite sites. Download it now!
RE: ? how cisco router handle the out-of-order ICMP echo-reply packets
There aren't sequence numbers with ICMP. And the timeout value is watched/triggered before the next ICMP is sent, so there shouldn't really be any ordering problem/interpretation anyway. HTH, Scott -Original Message- From: Zhao Ping [mailto:pzhao...@gmail.com] Sent: Tuesday, January 06, 2009 6:26 AM To: na...@merit.edu Subject: ? how cisco router handle the out-of-order ICMP echo-reply packets Hi, Does someone happen to know how the Cisco IOS handle the out-of-order ICMP echo-reply packets? print it as success or lose? Thanks, Zhao Ping
RE: ? how cisco router handle the out-of-order ICMP echo-reply packets
On Tue, 6 Jan 2009, Scott Morris wrote: There aren't sequence numbers with ICMP. And the timeout value is watched/triggered before the next ICMP is sent, so there shouldn't really be any ordering problem/interpretation anyway. Linux ping command does sequencing (so that part of your statement isn't accurate), and you can get out of order packets. It'll say a sequence number and ping time, and there really isn't any timeout, an ICMP packet can come back 60 seconds later and it'll be counted, even though there were 59 other packets send and returned in the meantime. $ ping localhost PING localhost (127.0.0.1) 56(84) bytes of data. 64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.023 ms 64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.020 ms In IOS, my interpretation anyway, is that the timeout value (2 seconds) mean that it really considers this packet as dropped, so no, in IOS you cannot get out of order packets, at least not that the CLI will show. If the ICMP response packet comes back after timeout value has triggered, it's considered lost. -- Mikael Abrahamssonemail: swm...@swm.pp.se
Re: Northern Ireland undersea branch to be implemented
Martin Hannigan wrote: Is all of this terrestrial network already in place? http://www.hiberniaatlantic.com/maps/HA_NIreland_Routes.pdf I understand that it isn't yet, but that it can be built out relatively quickly. Nick
Re: ? how cisco router handle the out-of-order ICMP echo-reply packets
Scott Morris wrote: There aren't sequence numbers with ICMP. And the timeout value is watched/triggered before the next ICMP is sent, so there shouldn't really be any ordering problem/interpretation anyway. FYI, from RFC 792: Sequence Number Description The data received in the echo message must be returned in the echo reply message. The identifier and sequence number may be used by the echo sender to aid in matching the replies with the echo requests. For example, the identifier might be used like a port in TCP or UDP to identify a session, and the sequence number might be incremented on each echo request sent. The echoer returns these same values in the echo reply. Steve
Re: ? how cisco router handle the out-of-order ICMP echo-reply packets
Steve Bertrand wrote: Scott Morris wrote: There aren't sequence numbers with ICMP. And the timeout value is watched/triggered before the next ICMP is sent, so there shouldn't really be any ordering problem/interpretation anyway. FYI, from RFC 792: My apologies. I should have actually used the subject to scope what you were saying. Steve
RE: ? how cisco router handle the out-of-order ICMP echo-reply packets
Guess I'll have to go back and look at wireshark output again... I didn't
recall seeing sequence number used in pings between Cisco devices, although
that may just be the implementation ('may be used') part.
I'll stand corrected. ;)
Scott
-Original Message-
From: Steve Bertrand [mailto:st...@ibctech.ca]
Sent: Tuesday, January 06, 2009 8:52 AM
To: s...@emanon.com
Cc: 'Zhao Ping'; na...@merit.edu
Subject: Re: ? how cisco router handle the out-of-order ICMP echo-reply
packets
Scott Morris wrote:
There aren't sequence numbers with ICMP. And the timeout value is
watched/triggered before the next ICMP is sent, so there shouldn't really
be
any ordering problem/interpretation anyway.
FYI, from RFC 792:
Sequence Number
Description
The data received in the echo message must be returned in the echo
reply message.
The identifier and sequence number may be used by the echo sender
to aid in matching the replies with the echo requests. For
example, the identifier might be used like a port in TCP or UDP to
identify a session, and the sequence number might be incremented
on each echo request sent. The echoer returns these same values
in the echo reply.
Steve
Re: Hirschmann Switches?
We have a good experience with Hirschmann (now Belden) industrial switches, OpenRail RS30 and Modular MICE series. They had some pretty funny software bugs with older software versions. We are using them in MAN ring networks with heavy multicast traffic. Cristian On Tue, Jan 6, 2009 at 8:27 AM, Paul Wall pauldotw...@gmail.com wrote: I'm looking for feedback from users of the Hirschmann (Belden) ethernet switches in a service provider environment. Private or public appreciated. Drive Slow, Paul Wall
Re: Hirschmann Switches?
Used a MACH4002 as multicast router at 25C3 (among many other locations in the conference/building network as pure L2 devices). Worked flawlessly. -- Niels. * cbr...@bofhserver.net (Cristian Bradiceanu) [Tue 06 Jan 2009, 16:27 CET]: We have a good experience with Hirschmann (now Belden) industrial switches, OpenRail RS30 and Modular MICE series. They had some pretty funny software bugs with older software versions. We are using them in MAN ring networks with heavy multicast traffic. Cristian On Tue, Jan 6, 2009 at 8:27 AM, Paul Wall pauldotw...@gmail.com wrote: I'm looking for feedback from users of the Hirschmann (Belden) ethernet switches in a service provider environment. Private or public appreciated. Drive Slow, Paul Wall
Re: Ethical DDoS drone network
David Barak wrote: Consider for a moment a large retail chain, with several hundred or a couple thousand locations. How big a lab should they have before deciding to roll out a new network something-or-other? Should their lab be 1:10 scale? A more realistic figure is that they'll consider themselves lucky to be between 1:50 and 1:100, and that lab is probably understaffed at best. Having a dedicated lab manager is often seen as an expensive luxury, and many businesses don't have the margin to support it. At the very least they should have a complete mock location (for an IT perspective) in a lab. Identical copies of all local servers and a carbon copy of their official template network. This is how AOL does it. Every change is tested in the mock remote site before the official template is changed and the template is pushed out to all the production sites. Justin
Re: Ethical DDoS drone network
Justin Shore wrote: David Barak wrote: Consider for a moment a large retail chain, with several hundred or a couple thousand locations. How big a lab should they have before deciding to roll out a new network something-or-other? Should their lab be 1:10 scale? A more realistic figure is that they'll consider themselves lucky to be between 1:50 and 1:100, and that lab is probably understaffed at best. Having a dedicated lab manager is often seen as an expensive luxury, and many businesses don't have the margin to support it. At the very least they should have a complete mock location (for an IT perspective) in a lab. Identical copies of all local servers and a carbon copy of their official template network. This is how AOL does it. Every change is tested in the mock remote site before the official template is changed and the template is pushed out to all the production sites. That's useful for testing changes to the remote site itself, but it doesn't do anything for testing changes to the entire WAN. I've seen _many_ routing problems appear in large WANs that simply can't be replicated with fewer than a hundred or even a thousand routers. The vendors may have tools to simulate such, since they need them for their own QA, support, etc. but they rarely give them to customers because that'd be another product they have to support... S smime.p7s Description: S/MIME Cryptographic Signature
RE: Hirschmann Switches?
If an Industrial Ethernet switch is required it may be productive to look at Ruggedcom products. Ruggedcom has a published upper operating range of +85 C, which we have deployed in outside non-HVAC enclosures in environments where the outside ambient temperature can reach +49 to +55 C for extended periods. The L2 software is reliable, supporting rapid spanning tree, and IGMP snooping, among other features. Short and Long range SFP optics (up to 80 Km) are available that are also spec'd out at +85 C operating range. -Original Message- From: Paul Wall [mailto:pauldotw...@gmail.com] Sent: Monday, January 05, 2009 9:27 PM To: NANOG list Subject: Hirschmann Switches? I'm looking for feedback from users of the Hirschmann (Belden) ethernet switches in a service provider environment. Private or public appreciated. Drive Slow, Paul Wall
Re: Ethical DDoS drone network
--- On Tue, 1/6/09, Justin Shore jus...@justinshore.com wrote: David Barak wrote: Consider for a moment a large retail chain, with several hundred or a couple thousand locations. How big a lab should they have before deciding to roll out a new network something-or-other? Should their lab be 1:10 scale? A more realistic figure is that they'll consider themselves lucky to be between 1:50 and 1:100, and that lab is probably understaffed at best. Having a dedicated lab manager is often seen as an expensive luxury, and many businesses don't have the margin to support it. At the very least they should have a complete mock location (for an IT perspective) in a lab. Identical copies of all local servers and a carbon copy of their official template network. This is how AOL does it. Every change is tested in the mock remote site before the official template is changed and the template is pushed out to all the production sites. I don't disagree at all: that is a straightforward way to anticipate *most* problems. What is does not and cannot validate is whether there is a scaling issue, and this is what doing live testing does give you. David Barak Need Geek Rock? Try The Franchise: http://www.listentothefranchise.com
Re: question about BGP default routing
KC Date: Mon, 5 Jan 2009 21:52:12 -0600 KC From: Kai Chen KC Will this default route 0.0.0.0/0 be exporting to AS-level KC neighbors? You can have it exported, or you can have it not exported. It depends how the route is known (eBGP? OSPF? static?) and what you set BGP to redistribute. Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.
Re: question about BGP default routing
cK Date: Tue, 6 Jan 2009 07:40:16 -0500 (EST) cK From: chloe K cK Why it needs default routes when running BGP? If you have a full table, you do not need default. It's even desirable to drop road-to-nowhere packets inside your network, before they clog up your connections. However, consider that you may encounter some problems -- such as insufficient RAM to deal with growing table size -- that leave you forced to take a partial table. Then what? If you're running BGP, you probably have more than one upstream, so you don't want static defaults (unless the next hop is a serial interface). To deal with this, you can have your providers originate default _and_ send a full table. Under normal circumstances, use a route map that nukes 0/0. If you find yourself in a jam, replace the route map with one that allows 0/0 and discard long paths, AS_PATHs that you consider troublesome, et cetera. You still have the benefit of directing certain routes to a specific provider, but with a smaller (partial) table. Finally, note that not every router needs full tables. Consider a peering router that exchanges traffic between a network's peers and customers. Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.
RE: [SPAM-HEADER] - Re: Northern Ireland undersea branch to be implemented - Email has different SMTP TO: and MIME TO: fields in the email addresses
It can be done very quickly. We've committed to fast delivery. The terrestrial conduit and fibre is ready to go ... Roderick S. Beck Director of European Sales Hibernia Atlantic 13-15, rue Sedaine, 75011 Paris http://www.hiberniaatlantic.com Wireless: 1-212-444-8829. French Landline: 33+1+4355+8224 French Wireless: 33-6-14-33-48-97. AOL Messenger: GlobalBandwidth rod.b...@hiberniaatlantic.com rodb...@erols.com ``Unthinking respect for authority is the greatest enemy of truth.'' Albert Einstein. -Original Message- From: Nick Hilliard [mailto:n...@foobar.org] Sent: Tue 1/6/2009 1:28 PM To: Martin Hannigan Cc: nanog@nanog.org Subject: [SPAM-HEADER] - Re: Northern Ireland undersea branch to be implemented - Email has different SMTP TO: and MIME TO: fields in the email addresses Martin Hannigan wrote: Is all of this terrestrial network already in place? http://www.hiberniaatlantic.com/maps/HA_NIreland_Routes.pdf I understand that it isn't yet, but that it can be built out relatively quickly. Nick
Estimate of satellite vs. Land-based traffic
All, Participting in a severe solar event EXERCISE. Can anyone give me an educated guesstimate of the percentage of backbone traffic that is satellite dependent vs. that which is totally land-based? Thanks Kevin Smith Information Systems Services Department of Community Affairs kevin.sm...@dca.state.fl.us [preferred] 850.922.9921 [voice] 850.487.3376 [fax] -- Sent from a BlackBerry Wireless Handheld Florida has a broad public records law and all correspondence, including email addresses, may be subject to disclosure.
Re: Estimate of satellite vs. Land-based traffic
On Tue Jan 06, 2009 at 03:34:31PM -0500, kevin.sm...@dca.state.fl.us wrote: Participting in a severe solar event EXERCISE. Can anyone give me an educated guesstimate of the percentage of backbone traffic that is satellite dependent vs. that which is totally land-based? Depends on the country. I suspect in the USA, it's close to 100% land-based. In places in central Africa, it's probably close to 100% satellite based. Simon -- Simon Lockhart | * Sun Server Colocation * ADSL * Domain Registration * Director|* Domain Web Hosting * Internet Consultancy * Bogons Ltd | * http://www.bogons.net/ * Email: i...@bogons.net *
Re: Estimate of satellite vs. Land-based traffic
Kevin, Satellite transport is common mainly in areas where land based infrastructure is not feasible. In developed nations this is almost exclusively the case. Satellite latency is far too high to rely on it for routine communications unless used as a last resort. Best regards, Jeff On Tue, Jan 6, 2009 at 3:34 PM, kevin.sm...@dca.state.fl.us wrote: All, Participting in a severe solar event EXERCISE. Can anyone give me an educated guesstimate of the percentage of backbone traffic that is satellite dependent vs. that which is totally land-based? Thanks Kevin Smith Information Systems Services Department of Community Affairs kevin.sm...@dca.state.fl.us [preferred] 850.922.9921 [voice] 850.487.3376 [fax] -- Sent from a BlackBerry Wireless Handheld Florida has a broad public records law and all correspondence, including email addresses, may be subject to disclosure. -- Jeffrey Lyon, Leadership Team jeffrey.l...@blacklotus.net | http://www.blacklotus.net Black Lotus Communications of The IRC Company, Inc. Look for us at HostingCon 2009 in Washington, DC on August 10th - 12th at Booth #401.
Re: Estimate of satellite vs. Land-based traffic
On Tue, 6 Jan 2009, kevin.sm...@dca.state.fl.us wrote: Participting in a severe solar event EXERCISE. Can anyone give me an educated guesstimate of the percentage of backbone traffic that is satellite dependent vs. that which is totally land-based? The last FCC statistics I found researching this last year. 2006 Satellites carry 0.22% of US international circuits. There are 14,346 US international circuits via satellite. http://www.donelan.com/overseas.html
Re: Ethical DDoS drone network
On Jan 7, 2009, at 1:05 AM, Stephen Sprunk wrote: I've seen _many_ routing problems appear in large WANs that simply can't be replicated with fewer than a hundred or even a thousand routers. Users can simulate many of these conditions themselves using various open-source and commercial tools, which've been available for many years. And again, it comes back to understanding the performance envelope of one's equipment, even without simulation. --- Roland Dobbins rdobb...@cisco.com // +852.9133.2844 mobile All behavior is economic in motivation and/or consequence.
Re: Ethical DDoS drone network
RD Date: Wed, 7 Jan 2009 08:50:46 +0800 RD From: Roland Dobbins RD I've seen _many_ routing problems appear in large WANs that simply RD can't be replicated with fewer than a hundred or even a thousand RD routers. RD Users can simulate many of these conditions themselves using various many != all It appears to be a question of what incremental benefit does one gain from real-world testing? RD open-source and commercial tools, which've been available for many RD years. I think that everyone agrees: No live testing until adequate lab testing has been performed. The disagreement seems to be over when/if live testing is necessary, and how much. Because it just wouldn't be a NANOG thread without analogies *grin*, I offer the following: drug certification, aircraft certification, automobile crash testing, database benchmarking. Even when a system is highly deterministic, such as a database, one still expects _real-world_ testing. Traffic flows on large networks are highly stochastic... and this includes OPNs, which I posit are futile to attempt to model. RD And again, it comes back to understanding the performance envelope RD of one's equipment, even without simulation. Very true. If one deploys an OSPF-happy network thinking that it scales O(n), one is in for a rude shock. Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.
Re: Ethical DDoS drone network
I propose that we create two Internets. One can be the testing Internet, and the other can be production. To ensure that both receive adequate treatment, they can trade places every few days. If something breaks, it can be moved from production to testing. The detection of hyperbole, sarcasm, and mathematical invalidity is left as an exercise to the reader. ;-) Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.
Re: Ethical DDoS drone network
On Jan 7, 2009, at 9:40 AM, Edward B. DREGER wrote: Even when a system is highly deterministic, such as a database, one still expects _real-world_ testing. Traffic flows on large networks are highly stochastic... and this includes OPNs, which I posit are futile to attempt to model. Sure. In many cases, it seems that there's a lot of talk about testing, after-the-fact, with relatively little analysis performed prior-to-the- fact to inform the design, including baseline security requirements. When one has a network/system in which the basic security BCPs haven't been implemented, it makes little sense to expend scarce resources testing when those resources could be better-employed hardening and increasing the resiliency and robustness of said network/system. --- Roland Dobbins rdobb...@cisco.com // +852.9133.2844 mobile All behavior is economic in motivation and/or consequence.
Re: Ethical DDoS drone network
RD Date: Wed, 7 Jan 2009 09:48:16 +0800 RD From: Roland Dobbins RD When one has a network/system in which the basic security BCPs RD haven't been implemented, it makes little sense to expend scarce RD resources testing when those resources could be better-employed RD hardening and increasing the resiliency and robustness of said RD network/system. Very true. Hey, it really _did_ break! is hardly a useful approach. Your post awakened my inner cynic: Perhaps there are people who look to stress-testing OPNs in hopes that the weakest link is elsewhere, so that they may point the proverbial finger instead of fixing internal problems. #include cost-shifting/patchining,smtp-auth,spf,urpf,et-cetera.h Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita DO NOT send mail to the following addresses: dav...@brics.com -*- jfconmaa...@intc.net -*- s...@everquick.net Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.
Re: Estimate of satellite vs. Land-based traffic
Jeffrey, While technically you are correct, I would say that you probably should also add a category for mobile communications LAND/SEA/AIR. The traffic for these will be increasing in time as vendors are starting to put switches and routers on-board spacecraft making applications that were once borderline, because of delay, more acceptable. Depending on what you are doing (eg. comm between two satellite ground stations, mobile or stationary) the application can benefit from from reduced RTT due to this innovation. One-way delay would thus be about 250ms. This is greater than the generally accepted 150ms for a voice call but with good voice quality 250ms is not bad. This of course is based on GEO sats. LEO or MEO satellites are much closer to the earth so the delay would be less but they present a whole host of other complexities. While satellites will probably never come close to the volume of ground-based comm, they will cater to niche markets, military, mobile and disadvantaged users. WRT Kevin's query, if you are concerned about a solar incident and it's affects on satcom, you might want to take a look at what user base (e.g. which mobile users and what impact loss of comm will have on what they are doing) is affected rather than understanding the volumes that are affected as this might provide a much more thorough understanding of any impact. But that is merely my two cents worth. -Donner Jeffrey Lyon wrote: Kevin, Satellite transport is common mainly in areas where land based infrastructure is not feasible. In developed nations this is almost exclusively the case. Satellite latency is far too high to rely on it for routine communications unless used as a last resort. Best regards, Jeff On Tue, Jan 6, 2009 at 3:34 PM, kevin.sm...@dca.state.fl.us wrote: All, Participting in a severe solar event EXERCISE. Can anyone give me an educated guesstimate of the percentage of backbone traffic that is satellite dependent vs. that which is totally land-based? Thanks Kevin Smith Information Systems Services Department of Community Affairs kevin.sm...@dca.state.fl.us [preferred] 850.922.9921 [voice] 850.487.3376 [fax] -- Sent from a BlackBerry Wireless Handheld Florida has a broad public records law and all correspondence, including email addresses, may be subject to disclosure.
Re: Estimate of satellite vs. Land-based traffic
Northern communities in Canada's arctic rely exclusively on satellite for voice/data. Not a lot of data flowing comparatively, but it is their only option so it is more of a mission critical thing than a backup.
Re: Estimate of satellite vs. Land-based traffic
On Tue, 6 Jan 2009, Paul Donner wrote: WRT Kevin's query, if you are concerned about a solar incident and it's affects on satcom, you might want to take a look at what user base (e.g. which mobile users and what impact loss of comm will have on what they are doing) is affected rather than understanding the volumes that are affected as this might provide a much more thorough understanding of any impact. But that is merely my two cents worth. Yep, consider the Galaxy IV satellite incident. The loss of a single satellite had a significant impact on its user population for several days/month. Other satellites can be moved into an orbital slot, and dishes can be re-pointed; but Galaxy IV lead to some interesting (i.e. unexpected to some users) failures. I'm not sure how many hospitals realized their in-house pager systems relied on a satellite.
Re: Estimate of satellite vs. Land-based traffic
JF Mezei wrote: Northern communities in Canada's arctic rely exclusively on satellite for voice/data. Not a lot of data flowing comparatively, but it is their only option so it is more of a mission critical thing than a backup. Also high latitudes are problematic as far as your link budget to geostationary satellites goes in the first place. Switching to an alternative satellite in the event of a failure may be more challenging as a result.
Re: Estimate of satellite vs. Land-based traffic
Satellites often sit at the edge of the network. The orbital last mile for individual users as well as in-country (Africa for e.g.) ISPs and Enterprise networks. When they go, often there is no backup (except maybe another satellite connection). Sean Donelan wrote: On Tue, 6 Jan 2009, Paul Donner wrote: WRT Kevin's query, if you are concerned about a solar incident and it's affects on satcom, you might want to take a look at what user base (e.g. which mobile users and what impact loss of comm will have on what they are doing) is affected rather than understanding the volumes that are affected as this might provide a much more thorough understanding of any impact. But that is merely my two cents worth. Yep, consider the Galaxy IV satellite incident. The loss of a single satellite had a significant impact on its user population for several days/month. Other satellites can be moved into an orbital slot, and dishes can be re-pointed; but Galaxy IV lead to some interesting (i.e. unexpected to some users) failures. I'm not sure how many hospitals realized their in-house pager systems relied on a satellite.
