Re: MAE-ATM Wire Speed PVC Interest Poll
On Mon, 11 Sep 2000, Nick Gerber wrote:
I don't have any MAE-ATM access ports, but I would be interested in how line rate ATM works. I supported the Sprint ATM backbone for several years and never heard of something like this before. Could you forward me some info or links? Or am I misunderstanding the meaning in your email?
A few people have asked me questions like this so I am clarifying to the list. BTW, I have had excellent positive response to my original email. If you are interested and haven't responded yet please do so. Currently MAE-ATM customers can only create what amounts to CBR PVCs to other peers by using a web interface called PeerMaker. This means that you must allocate a fraction of the capacity of your port to each of your peers which typically results in PVC sizes betweem 5 amd 10 Mbps if you have an OC3 port. Due the the configuration of the MAE-ATM switches, any traffic sent in excess of the configured PVC size is dropped (we have verified this repeatedly). This results in a large amount of wasted capacity and unecessary droppage of packets. Traffic tends to grow and shift; continual reconfiguration of PVCs is not realistic. By comparison, Pac Bell NAP and Ameritech NAP customers talk via wirespeed UBR PVCs, which generally results in better utilization of the service. Better in this case being measured by larger amounts of traffic being carried with less loss and less management cost. The benefit of using UBR vs CBR at an exchange for most users is based on the premis of connections not being saturated. Even in the case of a saturated connection CBR does not fix things; in fact it creates another bottleneck with a much lower saturation threshold.
mleber@he.net wrote:
MAE-ATM users, if you are interested in having the option to set a PVC to wirespeed (like Pac Bell or Ameritech) (which can increase your effective utilization of your MAE-ATM port and reduce management costs) please send me email with your name, your company name, your phone number and your email address. I will pass the collected list onto this manager (email below) at Worldcom. The information will be used for that purpose only.
Thank you,
Mike.
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---------- Forwarded message ---------- Date: Mon, 11 Sep 2000 13:11:42 -0400 From: Alla Reznik <Alla.Reznik@wcom.com> To: Mike Leber <mleber@he.net> Subject: RE: MAE OC40 requirements?? - Hurricane Electric (fwd)
Would be very very helpful - please send if you could, thanks
Alla Reznik Manager Int'l Internet/MAE/Paging/Packet WorldCom Business Markets V227-6441 or (703)343-6441
-----Original Message----- From: Mike Leber [mailto:mleber@he.net] Sent: Sunday, September 10, 2000 8:26 PM To: Alla Reznik Subject: RE: MAE OC40 requirements?? - Hurricane Electric (fwd)
If I could give you a list (with contact names and phone numbers) of MAE-ATM customers that want this feature would it help?
On Sun, 10 Sep 2000, Alla Reznik wrote:
Thanks for the feedback, Mike.
Alla Reznik Manager Int'l Internet/MAE/Paging/Packet WorldCom Business Markets V227-6441 or (703)343-6441
-----Original Message----- From: Mike Leber [mailto:mleber@he.net] Sent: Thursday, September 07, 2000 2:24 AM To: Alla.Reznik@wcom.com Subject: Re: MAE OC40 requirements?? - Hurricane Electric (fwd)
Our number one request is for wirespeed PVCs like Pac Bell NAP or Ameritech. This feature could be added with a checkbox in peermaker.
Date: Mon, 07 Aug 2000 15:17:41 -0400 From: Alla Reznik <Alla.Reznik@wcom.com> To: peering@he.net Subject: MAE OC40 requirements?? - Hurricane Electric
Dear customer, our records indicate that you are using OC12 MAE ATM service from WorldCom. We would like to find out from you if you have any plans to move up to OC48 level of service and what are your specific requirements for such service would be. As you might already know Worldcom does not offer MAE service above OC12 level at this time, but we recognize it as a requirements going forward and have made plans to offer it next year. However, we would like to hear from you and learn more about your requirements as well as timeframe as to when you are planning to make such move, so that we can respond in the best manner possible with the service suitable to your requirements.
Alexandra (Alla) Reznik WorldCom Business Markets Data and Enterprise Product Marketing Int'l Internet, MAE, and Packet Services (703) 343-6441 http://datamarketing.wcomnet.com/index.html
+------------------- H U R R I C A N E - E L E C T R I C -------------------+ | Mike Leber Direct Internet Connections Voice 510 580 4100 | | Hurricane Electric Web Hosting Colocation Fax 510 580 4151 | | mleber@he.net http://www.he.net |
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+------------------- H U R R I C A N E - E L E C T R I C -------------------+ | Mike Leber Direct Internet Connections Voice 510 580 4100 | | Hurricane Electric Web Hosting Colocation Fax 510 580 4151 | | mleber@he.net http://www.he.net | +--------------------------------------------------------------------------- +
-- Nick Gerber Sprint Broadband Wireless Group Voice: 913 534 7317 Pager: 877 344 3821 Email: nick.c.gerber@mail.sprint.com
+------------------- H U R R I C A N E - E L E C T R I C -------------------+ | Mike Leber Direct Internet Connections Voice 510 580 4100 | | Hurricane Electric Web Hosting Colocation Fax 510 580 4151 | | mleber@he.net http://www.he.net | +---------------------------------------------------------------------------+
Date: Mon, 11 Sep 2000 16:14:42 -0700 (PDT) From: Mike Leber <mleber@he.net> Sender: owner-nanog@merit.edu
Currently MAE-ATM customers can only create what amounts to CBR PVCs to other peers by using a web interface called PeerMaker. This means that you must allocate a fraction of the capacity of your port to each of your peers which typically results in PVC sizes betweem 5 amd 10 Mbps if you have an OC3 port. Due the the configuration of the MAE-ATM switches, any traffic sent in excess of the configured PVC size is dropped (we have verified this repeatedly). This results in a large amount of wasted capacity and unecessary droppage of packets. Traffic tends to grow and shift; continual reconfiguration of PVCs is not realistic.
By comparison, Pac Bell NAP and Ameritech NAP customers talk via wirespeed UBR PVCs, which generally results in better utilization of the service. Better in this case being measured by larger amounts of traffic being carried with less loss and less management cost.
The benefit of using UBR vs CBR at an exchange for most users is based on the premis of connections not being saturated. Even in the case of a saturated connection CBR does not fix things; in fact it creates another bottleneck with a much lower saturation threshold.
To further clarify things, Worldcom does not use CBR at the MAEs. It uses ABR. And ABR would be ideal if Worldcom used it as it was designed. The parameters for ABR are peak cell rate (PCR) and minimum cell rate (MCR). Bandwidth is reserved for the MCR and it is guaranteed to be available. Between MCR and PCR traffic is passed on a best-effort basis and is treated exactly like UBR traffic. So ABR would seem ideal for a MAE. You have a specified amount of reserved to provide for reliable access for contractual obligations and everything else works if the bandwidth is available just as if it was UBR. The only real problem is that the MAEs limit PCR to twice MCR. This simply wastes resources. PCR should be set to the minimum line speed of to two lines. If the PCR was set to this value, things would be much better. I would actually prefer this to UBR since UBR has no guarantees. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634
participants (2)
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Kevin Oberman -
Mike Leber