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Re: Sonet protection usage
by Danny McPherson 26 Jul '00

26 Jul '00

> Your experience leasing lines from RBOCs other than BellSouth and > Ameritech must be vastly better? Again, when ADMs and routers are in the same facility the local loop diversity issues are a non-issue. As Sean points out though, intra-facility connections fail, be it a result of human intervention or divine intervention. Also, maintenance affects this as well. > Now, in my experience, when routers _do_ fail, usually soon after > upgrading the software, APS won't help at all. The card is down, too. > IP has to route around the problem. > > Maybe this is some new use of the term "router"? Funny. You're clearly missing the point of the application. Consider the following: +-----+ | A3 | | | +-----+ / \ +-----+ +-----+ | A1 | | A2 | | | | | +-----+ +-----+ \w p/ +---------------+ | ADM-A | | | +---------------+ | | +---------------+ | ADM-B | | | +---------------+ /w p\ +-----+ +-----+ | B1 | | B2 | | | | | +-----+ +-----+ \ / +-----+ | B3 | | | +-----+ You're a provider with two locations (A & B), you own the ADMs (not the transmission facilities) and have only a single connection between the sites, say an OC12c that you lease from an RBOC. Now, you don't have another $100k (monthly) to give to the RBOC for a redundant, presumably diverse secondary OC12 connection, though you would like to be able to load new software on a router or perform maintenance such as hardware upgrades without losing connectivity between the sites. Considering you average ~300 Mbs on the OC12 buying a lower speed connection for redundancy isn't a viable option. So, you buy some ADMs (a capital expense which is likely less than one month of the recurring OC12 fees) and do inter-router APS at the site. Since APS isn't required on both sides (or in the network), you could even do one side at a time. The OC12 connection from the telco may or may not be protected. Under normal conditions the ADMs would transmit frames ingress from the network to both tributary ports (routers) and the inactive routers (A2 & B2, both inactive protect circuits at this point) are responsible for discarding the frames. The ADM would only transmit the ingress signal from the active tributary port to the network. The ADM and routers communicate via the K1 & K2 SONET bytes. Now, you want to do maintenance on B1 so you simply trigger a force switch to the protect circuit from the protect router interface. This in essence forces the ADM to use B2 as the active circuit. B1 is notified via the ADM (K1/K2) and becomes inactive, while B2 frames will be transmitted to the network. This is an overly simplistic model, though I hope the application has been better demonstrated. And again, it becomes even more interesting when the OC12 is trans-oceanic, or its an OC48 and the only viable completely diverse option requires 3 times the circuit route miles (which you pay for) and a few million dollars to provision a diverse fiber path into the facility, etc.. I assure you that it has it's uses and is employed by both network service providers (which in _this definition I refer to as owning the transmission facilities), as well as ISPs. There are lots of higher layer issues such as interaction with the IGP that impact convergence times considerably (e.g. the fact that when B2 becomes active above a new adjacency must be formed with A1, the remote router, or SPF run timers throttling rerun when the new adjacency is reported because of a recent run triggered by the report of the failure itself), but it's still far, far better than doing nothing at all. > Virtually every router I've installed, even "ancient" NetBlazers > and Ascends sitting out at the customer sites, has been stable > for years without interruption. OTOH, links fail often, in ice > storms, in rain, on windy days, even for no known reason at all! As for this, let me let you in on a little secret: There's always a reason the links fail. (Just kidding! ;-). HTH, -danny

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Re: Sonet protection usage
by Danny McPherson 26 Jul '00

26 Jul '00

> Think about it -- are they really provisioning two circuits, leaving > one available as a backup? Of course not! I think you missed on of my points, which was APS on the trib side of the ADM, only a small mention of APS on the network side. If you can't figure out whether you've two circuits sitting there you've got bigger problems... > This may be a useful feature for voice circuits, where most of the > capacity sits idle most of the time. It's worse than useless for data. Again, I think you're missing the application wrt it residing on the trib side of the ADM -- to protect against router failures -- continuing to use the same network portion (i.e. the expensive portion) of the connection. > APS was designed to protect against the failure of the electronics > for a single fiber in a cable. Often, a dozen other circuits are > "protected" by a single APS. It's a ripoff. Perhaps in your experience, though I can argue quite the contrary, especially when your company owns the the transmission facilities. Though again, I was referring primarily to local protection against router failure on the trib side of the ADM. > Of course, the usual failure mode is backhoe fade, not electronics. > In which case, that APS circuit was cut along with the rest. Of course, backhoes don't normally work inside PoPs, which is the application of APS I was referring to. Routers do fail though (often more than links), and APS has been demonstrated to work relatively well for protecting against such failures. > For transoceanic links, diverse APS is even more unlikely, and unless > you are paying serious money, you won't be a priority over the other > hundred customers that are sharing that APS circuit. Not on the trib side, when protecting against router failures. > Diverse links _are_ the only _real_ protection. You might even get > what you pay for.... And in the short term, you at least get twice > the bandwidth Again, APS w/two local links to an ADM sufficiently protect against a local router failure. -danny

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Sonet protection usage
by Steve Feldman 26 Jul '00

26 Jul '00

A quick poll: Are many ISPs taking advantage of SONET APS protection to provide port or router redundancy on short (metro-area) circuits? Or is it more typical to get two circuits and load-share? Or just not bother? Thanks, Steve

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Re: Sonet protection usage
by Sean Donelan 26 Jul '00

26 Jul '00

On Tue, 25 July 2000, Danny McPherson wrote: > > Of course, the usual failure mode is backhoe fade, not electronics. > > In which case, that APS circuit was cut along with the rest. > > Of course, backhoes don't normally work inside PoPs, which is the application > of APS I was referring to. Routers do fail though (often more than links), > and APS has been demonstrated to work relatively well for protecting against > such failures. Although backhoes are often publically identified as the cause of problems, it turns out 71% of the reportable telephone outages last quarter were due to problems inside the carrier's control (i.e. inside the C.O.) according to ATIS/NRSC's calaculations. CO's are dangerous places for network equipment.

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Re: Sonet protection usage
by Danny McPherson 26 Jul '00

26 Jul '00

I should clarify. The "ADM trib" I'm referring to here is when the transmission gear (ADM) is located in the same facility as the routers and local loops are a non-issue. As for two local loops w/APS, one protecting the other, there are certainly precautions that can be taken to avoid a great deal of the problems that folks have shared here over the years, some obvious some not. But simply handing over another $100K for a second port, simply to protect against router failures, isn't always a sensible .. or viable option. -danny

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FRF.9 compression
by Mufti Ahmed 26 Jul '00

26 Jul '00

i'm trying to do sometype of Frame Relay compression between a Bay router and a CiscoRouter. Nortel states that they do not do FRF.9 which is a standard Frame Relay comp. because they haven't gotten much of a demand for it. Are there any other types of compression algorithms for Frame Relay and any websites that are helpful ? He mentioned Hi/fn compression but i'm not finding much info on this either. Any help is appreciated. Thanks Mufti Nayeem Ahmed Network Systems Engineer Market Data Networks Reuters America Inc. (212)-603-3595 ----------------------------------------------------------------- Visit our Internet site at http://www.reuters.com Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Reuters Ltd.

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New? domain name registration scam
by Chris Cappuccio 25 Jul '00

25 Jul '00

There is a new company called "Electronic Domain Name Monitoring" which you may get letters or faxes from... They read something like: "*** FINAL NOTICE *** FINAL NOTICE *** URGENT NOTICE OF IDENTICAL DOMAIN NAME APPLICATION BY A THIRD PARTY Please be advised that the above noted domain name has been submitted for registration, consequently, it is our opinion that this application may be submitted in bad faith for one or more of the following reasons......" Basically, this company becomes an affiliate to various hosting providers and registration resellers, possibly even to Network Solutions itself, although I was not able to get specific information. It asks them to send it new registration requests before they are approved. It then notifies anyone with a similar domain name or trade mark that the domain is being registered, and if so, it asks the registrar to prevent the registration, and instead registers the domain name with Network Solutions for the owner of the similar domain name or trade mark holder. Why is this a scam? This company presents itself as an authority, and acts as if it has official officers who are part of some team that regulates the Internet. Instead it just diverts registrations to Network Solutions!!! Short of saying it is a branch of the US government, they do a lot to make themselves sound official on the phone. The letter they send out looks scary, using lots of legalese, or like a Publisher's Clearing House sweepstakes joke, depending on how you read it. "In addition to remedies provided for by the Uniform Domain Name Dispute Policy, Section 4a (1)(2)(3) & b (1)(2)(3)(4), EDNM provides existing registrants, trademark and service mark owners with a first-right-to-use preference on domain names which are identical or confusingly similar to their own." Now, I don't think notifying people in advance because their domain name is being registered with a different extension and giving them the option to take the new registration is fair, or even legitimate, but this topic is already strecthing it for this mailing list. -- "Should we now be comfortable with a 'trust us, we're the government' approach?" he said. "I don't think anybody on this committee shares that view." -John Conyers, House Judiciary Committee

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Re: UBR at MAE-East ATM, anyone? (fwd)
by Alex 25 Jul '00

25 Jul '00

As you all may recall, a little while I ago I started a thread about UBR at MAE-*-ATM. Since then, I've found http://www.mae.net/~feldman/presentations/NANOG-May99/mgp00006.html (which I must have missed).. Questions to WCom about this have been met with a nifty black-hole affect. Is there a demand for this? Do we want UBR?

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any ISPs using dynamic dns?
by Eric A. Hall 24 Jul '00

24 Jul '00

Hi, Quick question: are any ISPs using Dynamic DNS for their end-user addressing and naming, or is everybody using fixed assingments for this still? Do any of the cable or xDSL vendors even support DDNS to anybody's knowledge? Thanks -- Eric A. Hall http://www.ehsco.com/ Internet Core Protocols http://www.oreilly.com/catalog/coreprot/

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who is peer?
by noc-eng＠gurlmail.com 24 Jul '00

24 Jul '00

sirs and madams, our noc inform us of down peer on mae east router... MAE-East#show ip bgp sum | include Active 129.21.60.174 4 4385 18542 632128 0 0 0 1d03h Active this resolve to mae-east.csh.rit.edu host, not mae fddi or atm ip. maybe ebgp multi hop. contacted appliedtheory noc does not know vci/vpi or switch port. pls help! ________________________________________________________________________ --> get your free, private gURLmail account at http://www.gURLmail.com !!

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