Multi-link Frame Relay OR Load Balancing
We are in the process of updating our internet connection to 8 t1's bound together. Due to price, our options have been narrowed to AT&T and MCI. I have two questions: 1. Which technology is better for binding t1's: multi link frame relay (mci's) or load balancing (att's) 2. Which company has a better pop in Atlanta: mci or att? We are in the Chattanooga TN area and our current connection is 6 t1's through att but they will only bond 4 so they are split 4 and 2. Bryce Enevoldson Information Processing Southern Adventist University
On Thu, 16 Sep 2004, Bryce Enevoldson wrote:
We are in the process of updating our internet connection to 8 t1's bound together. Due to price, our options have been narrowed to AT&T and MCI. I have two questions: 1. Which technology is better for binding t1's: multi link frame relay (mci's) or load balancing (att's)
of course, as always... not mci's view on the world ;) depends on what you want... do you want more than a 1.5mbps flow to pass? or do you just want to get 9mb of bandwidth and you don't care about max flow size? The MFR stuff will allow your link to look like a 9mb path, not 6 1.5mb paths. The load balancing makes it look like 6 l.5mb paths.
2. Which company has a better pop in Atlanta: mci or att?
i'll avoid this question since I'm not equiped to answer as anything but a marketting answer :)
We are in the Chattanooga TN area and our current connection is 6 t1's through att but they will only bond 4 so they are split 4 and 2.
Some folks have said in the last that over 6mb of bandwidth it might be better/cheaper/easier to just get a fractional/burstable DS3 to meet your needs. -Chris
On Thu, 16 Sep 2004, Bryce Enevoldson wrote:
We are in the process of updating our internet connection to 8 t1's bound together. Due to price, our options have been narrowed to AT&T and MCI. I have two questions: 1. Which technology is better for binding t1's: multi link frame relay (mci's) or load balancing (att's)
It depends on what you mean by better. Multilink is more CPU-intensive but is nicer to such things as voice that don't deal well with packets arriving out of order. Load balancing can be per packet or per destination (or flow). Per-packet allows for aggregation of the multiple paths for a large flow between two specific points but can give voice and similar services problems with reassembly. So "better" will depend on the nature of your traffic. At that speed I would highly recommend a DS-3 instead of either of the above. -- Jay Hennigan - CCIE #7880 - Network Administration - jay@west.net WestNet: Connecting you to the planet. 805 884-6323 WB6RDV NetLojix Communications, Inc. - http://www.netlojix.com/
FWIW, I asked about MLFR on the cisco-nsp and one person responded indicating he worked for some time with Cisco on trying to get MLFR to work but never resolved out of order and dropped packet issues. What hardware are you considering using to do MLFR ? Please let me know how things go as MLFR would be a nice option on some parts of my network. James H. Edwards Routing and Security Administrator At the Santa Fe Office: Internet at Cyber Mesa jamesh@cybermesa.com noc@cybermesa.com http://www.cybermesa.com/ContactCM (505) 795-7101
je> Date: Thu, 16 Sep 2004 16:44:48 -0600 je> From: james edwards je> FWIW, I asked about MLFR on the cisco-nsp and one person je> responded indicating he worked for some time with Cisco on je> trying to get MLFR to work but never resolved out of order je> and dropped packet issues. What hardware are you considering I must have missed your post, or I'd have chimed in. I've noted MFR flakiness (dropped packets, sudden interface down, additional links become unbonded and refuse to bond again, MTU troubles with MPLS, wedged processes, etc.) on 12.3 and 12.3T. Bryce, you might also consider an M13 mux if worried about loop reliability. However, at this point, I'd place my bets on a DS3 loop as opposed to several MFR-ified T1s. :-/ 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: davidc@brics.com -*- jfconmaapaq@intc.net -*- sam@everquick.net Sending mail to spambait addresses is a great way to get blocked.
In my experience the breakeven point for a Frame Relay DS3 is 6 DS1 circuits. DS3's tend to be more reliable than DS1's as the ILEC usually installs a MUX at your site instead of running to the nearest channel bank and running the T1's over copper with a few repeaters thrown in for good measure. Another nice thing about DS3's is that it is easy to scale bandwidth in the future by modifying the CIR on your link. Another feature is that since the link is faster the serialization delay is lower which will give you better latency and last but not least PA3+ for Cisco 7[2|5]xx routers are inexpensive and give you one call for service not a separate call for the CSU/DSU's and the serial line card you need to support a multilink solution. Scott C. McGrath On Thu, 16 Sep 2004, Bryce Enevoldson wrote:
We are in the process of updating our internet connection to 8 t1's bound together. Due to price, our options have been narrowed to AT&T and MCI. I have two questions: 1. Which technology is better for binding t1's: multi link frame relay (mci's) or load balancing (att's) 2. Which company has a better pop in Atlanta: mci or att?
We are in the Chattanooga TN area and our current connection is 6 t1's through att but they will only bond 4 so they are split 4 and 2.
Bryce Enevoldson Information Processing Southern Adventist University
Scott McGrath wrote:
In my experience the breakeven point for a Frame Relay DS3 is 6 DS1 circuits. DS3's tend to be more reliable than DS1's as the ILEC usually installs a MUX at your site instead of running to the nearest channel bank and running the T1's over copper with a few repeaters thrown in for good measure.
I'll second that. Our ILEC extended our existing SONET node (for the PBX in another building) to our machine room (couldn't push DS3 over copper that far). Now, if they'd just terminate the old T1s at the new node and not push them over local copper from there to the machine room, we would be sitting pretty.
Another nice thing about DS3's is that it is easy to scale bandwidth in the future by modifying the CIR on your link. Another feature is that since the link is faster the serialization delay is lower which will give you better latency and last but not least PA3+ for Cisco 7[2|5]xx routers are inexpensive and give you one call for service not a separate call for the CSU/DSU's and the serial line card you need to support a multilink solution.
Ditto. We have one in a 7204 with a CIR of 30Mb. Handles it quite nicely, replaced 5 T1s on load-sharing per-packet link. Jeff
3 quick notes-- Neither MLFR/FRF.16 (MCI's implementation) nor the corresponding CPE require external DSUs. The service may utilize internal DSUs (whether on Cisco CPE or Tasman) just as a tiered/fractional DS3 would. ATM-IMA could be considered wasteful of bandwidth as you would have to live with the ATM cell tax reducing usable bandwidth by about 25%. FRF.16 allows for much lower overhead through frame relay encapsulation. FRF.16 also allows for losing circuits within a bundle or even designating a threshold number of circuits for when to consider a link "down" (useful in failover scenarios). Another minor point is that DS3s are tiered by many large providers through timing at the provider edge DSU/linecard vs. CIR (even though FR encaps may be used). Given all that, a fraction DS3 may still be a better option if the telco loop is reasonable... Bryant Rump Advanced Internetworking Booz Allen Hamilton rump_bryant@bah.com -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Jeff Kell Sent: Thursday, September 16, 2004 10:55 PM To: Scott McGrath Cc: Bryce Enevoldson; nanog@merit.edu Subject: Re: Multi-link Frame Relay OR Load Balancing Scott McGrath wrote:
In my experience the breakeven point for a Frame Relay DS3 is 6 DS1 circuits. DS3's tend to be more reliable than DS1's as the ILEC usually installs a MUX at your site instead of running to the nearest channel bank and running the T1's over copper with a few repeaters thrown in for good measure.
I'll second that. Our ILEC extended our existing SONET node (for the PBX in another building) to our machine room (couldn't push DS3 over copper that far). Now, if they'd just terminate the old T1s at the new node and not push them over local copper from there to the machine room, we would be sitting pretty.
Another nice thing about DS3's is that it is easy to scale bandwidth in the future by modifying the CIR on your link. Another feature is that since the link is faster the serialization delay is lower which will give you better latency and last but not least PA3+ for Cisco 7[2|5]xx routers are inexpensive and give you one call for service not a separate call for the CSU/DSU's and the serial line card you need to support a multilink solution.
Ditto. We have one in a 7204 with a CIR of 30Mb. Handles it quite nicely, replaced 5 T1s on load-sharing per-packet link. Jeff
participants (8)
-
Bryce Enevoldson -
Christopher L. Morrow -
Edward B. Dreger -
james edwards -
Jay Hennigan -
Jeff Kell -
Rump Bryant -
Scott McGrath