September 1998 - Test - lists.nanog.org

Re: IXC Fibre cut IL,OH
by Sean Donelan 20 Sep '98

20 Sep '98

brad(a)null0.qual.NET (Bradley Reynolds) writes: >On a side-note, if you are in the ameritech service area, >ixc's 800 number translation is not working. You get to >hear a non-standard 'all circuits are busy'. If you need >to reach them, call their austin number 5124273700 This is the third such incident I know of where a carrier outage has also affected the ability to contact the carrier's network control center. So far most of the carriers and network operators I've spoken with don't consider this a major concern. A few are concerned, but they are in the minority. I know, been there done that. I keep hoping one day some folks will go "Hmm, maybe he has a point and we should do something." Although everyone uses them, 1-800 numbers have some interesting vulnerabilities for NOC's to rely on them to contact other NOCs. I worry that the expansion of CLECs into local service will bring similar single points of failure to local exchange numbers serving NOCs of those carriers. Its good that you use your own services. But when every method of telecommunications (phone, fax, pager, cell, internet, etc) to your NOC all goes through the same provider, I worry about the affect of a wide-spread outage at that provider on the ability for other NOCs to exchange information with that provider. Fire drills are a good start, but without more analysis, its difficult to predict how the system will react under real conditions. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Re: what's channellized E1?
by sully＠mail.usinternet.com 20 Sep '98

20 Sep '98

I'm not 100% sure about Euro T1's, but I believe its this... T1 - can be used for data in different forms. Running Frame, ATM.. etc A channelized T1 is provisioned to have 64k channels used for data/voice (ISDN etc). --Tim At 04:33 PM 9/18/98 +0800, you wrote: >Hi friends, > >A very very basic question: >What does "channellized E1" mean? What's its difference from a "normal" >E1 connection? > >reply to my mail box, if you think such message is too basic posting >on nanog, thanks. > >regards, > >Yu Ning >-- >___________________________________________* > >Yu Ning >ATM R&D Centre of >BUPT (Beijing U. of Posts&Telecom) >Beijing (ZIP:100876, MBox:147#), P.R.China >Ideas ONLY reflect my own views,:-) >___________________________________________ >

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Re: FCC outage reports
by Sean Donelan 19 Sep '98

19 Sep '98

shields(a)crosslink.NET (Michael Shields) writes: >You'd also want to look at more than just the count of outage reports; >the size of the outages matters, the total size of the network, and >the MTTR. If you "had to" distill it to a single number I suppose >percentage uptime is the one to use. The problem with percentage uptime is the law of large numbers. You need a huge disruption affecting a lot of customers for a long time to move the uptime percentage. As a customer I don't really care how much everyone else circuits were up. I only care about how much my circuits are up. If my AT&T circuit is down, it doesn't matter to me that 99.99999999999999999% of all AT&T's other circuits are working. >I'm not sure fiber cuts are common enough to make a meaningful >statement about the reliability of one carrier vs. another. I agree. The initial fiber cut isn't that meaningful. I have no hypothesis why backhoes (or other natural hazards) would prefer one carrier's fiber over another carrier's fiber. WilTel's initial plan of putting fiber inside steel gas pipelines not withstanding. Hence my original statement that there is no difference between the carriers based on just fiber cuts. Its like calculating the probability of a coin flip, just because one carrier had fewer fiber cuts this year doesn't seem to be a good predictor how many fiber cuts they will have next year. But how the carrier reacts after the fiber cut is an area you can make statements about the differences between one carrier vs. another. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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CHI contact issue..
by Richard Irving 19 Sep '98

19 Sep '98

Thanks gentlemen, CHI contacted me immediately, (I love the nanog list as a back up contact :). According to on-site technicals there is a fiber cut at "Midwest Relay", I am not sure how many yet. DS3's... But, emergency circuits are getting priority at 1 hour 30 minutes est. Have a nice saturday. :(

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Re: How to loadshare over many E1 links
by Hank Nussbacher 19 Sep '98

19 Sep '98

At 11:56 AM 9/18/98 -0400, Leo Bicknell wrote: On a slightly related matter, does anyone know how to load balance non-parallel links to a BGP peer? Thanks, Hank >In article <19980918095708.B10051(a)skriver.dk> you write: >>How would you loadshare over many (>6) parallel E1 links. Currently we >>do it by connecting them directly to the Cisco's in each end, and do >>CEF based per-packet loadsharing, it works fine, but support a max of >>6 E1's ... > > Cisco has a nice white paper on this: >http://www.cisco.com/warp/public/733/adap/multi/althb_wp.htm > > I think Multilink PPP may be your answer, as it goes >up to 8 links. There is a CPU hit though, I've never tried >Multilink on a high speed interface so I don't know how bad >it might affect the router. > >-- >Leo Bicknell - bicknell(a)dimension.net >Network Engineer (CCIE #3440) - Dimension Enterprises >1-703-709-7500, fax, 1-703-709-7699 > >

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Re: How to loadshare over many E1 links
by shields＠crosslink.net 19 Sep '98

19 Sep '98

In article <c=US%a=_%p=BAIS%l=MERCURY-980918163103Z-10472(a)mercury.balink.com>, "Martin, Christian" <CMartin(a)mercury.balink.com> wrote: > I meant the latter. I knew that there were switch to switch FDX > capabilities - I'd never seen a router interface or NIC though. Cool. For PC platforms, I've been happy with both Tulips and Intel eepro100b's at fdx 10BT. Both cards are real cheap and have 100BT support as well. Catalyst 1900s do fdx 10BT, as do 3com 1000s (but you'll want current firmware). I don't think Cisco has fdx 10BT interfaces but the new-style (VIP-type) FEIP2 will do fdx 100BT. I'm not sure if hdx/fdx autonegotiation works at 10BT -- I don't trust it anyway. -- Shields, CrossLink.

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RE: got any good documents ?
by Goldstein_William＠bns.att.com 19 Sep '98

19 Sep '98

Seem to remember looking over it vaguely. As I remember, it dealt more with LAN than WAN issues and had little on MPOA. Bill Goldstein Senior Internet Specialist AT&T wgoldstein(a)att.com TEL:(412)642-7288 ---------- From: pat Sent: Friday, September 18, 1998 10:12 PM To: Goldstein, William Cc: pat; jamie; kbrown; nanog Subject: RE: got any good documents ? Any comments on this one: Tcp/Ip over Atm : A No-Nonsense Internetworking Guide by Berry Kercheval ... particularly from the view of ATM-based enterprise backbone running IP. At 12:05 PM 9/16/98 , Goldstein_William(a)bns.att.com wrote: > Dan Minoli has published a couple of good books on ATM this year. > > Also, Darren Spohn and Dave McDysan have a new one coming out in a few > weeks that is supposed to be very comprehensive. -- Patrick Lee <pat(a)patlee.org> <<File: RE_ got any good documents _.TXT>>

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Question- Contacts at CHI-AADS during weekend
by Richard Irving 19 Sep '98

19 Sep '98

Hrmmmmm, Seems like the CHI-AADS emergency contacts have changed... At least for the weekend... Anyone have new outage contacts, for a Saturday ???

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Re: FCC outage reports
by shields＠crosslink.net 19 Sep '98

19 Sep '98

In article <980918150644.eb48(a)SDG.DRA.COM>, Sean Donelan <SEAN(a)SDG.DRA.COM> wrote: > FCC outage reports by year and inter-exchange carrier > > 1992 1993 1994 1995 1996 > AT&T 3 15 7 18 17 > MCI 13 12 19 9 15 > Sprint 3 11 3 12 9 > WorldCom NA NA NA 7 13 > > There are all sorts of normalization problems, different reporting [...] You'd also want to look at more than just the count of outage reports; the size of the outages matters, the total size of the network, and the MTTR. If you "had to" distill it to a single number I suppose percentage uptime is the one to use. I'm not sure fiber cuts are common enough to make a meaningful statement about the reliability of one carrier vs. another. -- Shields, CrossLink.

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How to loadshare over many E1 links
by Jesper Skriver 19 Sep '98

19 Sep '98

Hi, How would you loadshare over many (>6) parallel E1 links. Currently we do it by connecting them directly to the Cisco's in each end, and do CEF based per-packet loadsharing, it works fine, but support a max of 6 E1's ... I've been thinking om something similar to the Larscom inverse MUX (http://www.larscom.com/t3ft3/t3_megae.htm) but this one only support 4 E1's, then I can use multiple i-mux's and loadshare over the 8M links they provide, but it seems like a poor solution. Yes, I do know that a E3 would be a far better choice, but our ADM (Add-Drop-Multiplexer??) at this specific location only support E1's :-( /Jesper -- Jesper Skriver (JS249-RIPE), Network manager Tele Danmark DataNet, IP section (AS3292) One Unix to rule them all, One Resolver to find them, One IP to bring them all and in the zone to bind them.

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