My precious! It further occurs to me that even if you have radio built-in bw management you would also be pretty smart to have bw management enabled at the head-end, too. Why? Radio built-in bw management will block customer excess rate inbound customer traffic from wasting your rf capacity between CPE & Access Point, but if you've got rf backhaul to the site you need head-end bw management as well to block excess rate outbound customer traffic from wasting the rf backhaul bw before it ever reaches the AP's outbound bw management. And the outbound bw is typically greater than the inbound bw anyway. So it now looks prudent to me to have BOTH bw management built into the radios, AND at the head-end.
Rich ----- Original Message ----- From: Jason To: WISPA General List Sent: Thursday, January 25, 2007 2:31 PM Subject: Re: [WISPA] Advanced Bandwidth Management From what I understand, there are many types of qdisc (HTB, CBQ, Prio, on and on) that you can invoke with the 'tc' linux command. HTB is the 'Hierarchical Token Bucket' that you hear a lot about because it works well. HTB should not be confused with 'Hierarchical TOLKIEN Bucket' that has something to do with the Lord of the Rings. 'Leaky Bucket' is a reference to my brains as I try to grasp bandwidth shaping. Jason Rich Comroe wrote: > Great reference and I've learned a tremendous amount from this list. I learned that I have been mis-using the term Leaky Bucket. I now understand that what Jason described to the list is Token Bucket (I was totally wet in my earlier reply calling it Leaky Bucket). > > Radios that implement bw management vary considerably in sophistication of their bw management algorithms. I'm really impressed with the Alvarion bw management. Canopy has bw management built-in as well, but it seems less sophisticated. I'm also impressed with what I've learned Linux advanced bw management can do at the head-end if your radios don't. > > Given radios can be bridged or not, bw management in the in-radio implementations seem better ... because I don't see how head-end bw management can distinguish between bw to multiple destinations behind the same customer radio if the radios are bridged. Even if the radios are not bridged, then I'd see in-radio bw management as 'still' better because bw limited at the customer radio doesn't chew up inbound rf capacity, while in head-end bw management the rf inbound capacity gets burned whether the traffic is ultimately limited or not. > > Anyways, I'm getting a great deal from the discussion, and would love to hear if other radios have built-in bw management and what method is use for comparison (any Trango users who could possibly comment?). > > Rich > From: Ryan Langseth > To: WISPA General List > Sent: Thursday, January 25, 2007 12:44 AM > Subject: Re: [WISPA] Advanced Bandwidth Management > > > > On Jan 24, 2007, at 8:25 PM, Rich Comroe wrote: > > > Thanks much. I love it when you talk technical! Sorry, couldn't > > help it... > > > > No really, the devil is always in the details in these things. > > This is just the detail I was looking for. After I digest I hope I > > may send questions your way off-list. Still hoping operators using > > other brands will share what bw management algorithms they may have > > built-in. > > > If you are looking for a better understanding of some of the traffic > control systems, the Linux Advanced Routing and Traffic Control > manual is a good place to look. Starting at chapter 9, it goes into > some detail on how some of the the algorithms available work and how > to implement them. > > http://lartc.org > http://lartc.org/howto/lartc.qdisc.html > > > thanks again, > > Rich > > > -Ryan > > -- > InvisiMax > Ryan Langseth > Systems Administrator > [EMAIL PROTECTED] > work: (218) 745-6030 > > > > > > > -- > WISPA Wireless List: wireless@wispa.org > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
