We have 4 T1s at our headend. 5700BH (P9s at 7.1.4) backhaul to Micro hub. 5700BH Backhauls to remote sites using AP/SM or bridge/omnis. It has been working fine, but the latest T1 does not seem to be making any difference. Is there a limit to the number of T1s we can use? There is a tentative plan to add 2 more T1s if feasible.
Thanks in advance for any help.
Carol
I would Def. upgrade the firmware on your BH’s 7.1.4 is ANCIENT. and 9.0/9.3 actually offer more PPS than the old firmware. so i would start there.
We cannot go any higher than 7.3.6 as we have all old equipment, some of it is even P7. This is somewhat of a shoestring operation, we have virtually no budget for new updated equipment so must make do with what we have and any used spares we can acquire.
Thanks for the reply,
Carol
BH10 or BH20?
Our backhauls are 5700BH10.
Thanks, Carol and Frank
Frank wrote: We cannot go any higher than 7.3.6 as we have all old equipment, some of it is even P7. This is somewhat of a shoestring operation, we have virtually no budget for new updated equipment so must make do with what we have and any used spares we can acquire.
Thanks for the reply,
Carol
You said in your original Post your Main BH are P9's , not P7's. IF they are truely P9's, they CAN go up to 9.0 . And since thats your main BH i would try to make it as efficient as possible.
Frank wrote: Our backhauls are 5700BH10.
Thanks, Carol and Frank
with a BH10 you will be lucky to see 8mbps aggregate. Im guessing you have the DL percentage at 50% , thats only 4mpbs . so adding more T1's would not net you anything, as your BH cant support the bandwidth.
you could adjust DL % but obviously you will lose some upload speed
One of the “main” backhaul units is a P9, the other is a P8. Both units have the capability to be set to 20Mbps, but when we tried that setting the jitter was really high, always between 6 and 10. The distance is 2.46 miles, reflector on one end. The system worked but we worried this was a problem. When we took the units to 10Mbps they became stable, jitter 1/2.
The other two sets of 5700BHs in the system are a mix of P8 and P9, all but one can only do 10Mbps. We did not think we could mix that so have stuck with 10Mbps. What benefit would we get from going up to an 8x rev on the main link, if that is possible with the P8 to P9? which 8x rev was most stable? We acquired an AP (it was a P8) that was at 8.2 Hardware Scheduling and we could not use it in our system, it would not communicate with our SMs, since we are Software Scheduling only. We were able to take it back down to a usable state, but have avoided going above 7.3.6 since that time.
We did adjust the DL% to 25% and it seemed to improve…
Thanks for all the input.
Carol and Frank
In 2X Jitter up to 9 is acceptable. go ahead and run it and then to a link test. If you can get better than about 70% efficiency you can leave it in 2X.
the BH feeds your hub - how many BH’s run off that hub and what frequencies are they?
Are you doing any kind of monitoring of traffic, latency, and radio performance?
We are planning return to the BH20 mode for the main link based on your input Jerry. We have two other 5700BHs out of the Micro. One is capable of being a 20 but the current slave is only BH10. We have a BH20 spare we will put in that location. The other BH out of the Micro is BH10 only and so is the slave. We don’t currently have any other BH20 spares but if we see gain on the other link we will try to acquire some more BH20s. We also have three 5200 APs out of the Micro.
Thanks for your help
Carol and Frank
I have used P9 BH20’s @ 900/pair.
There are 4 pairs available at this price.
I would definitely run the BH’s at 20MB if link test are good. You will only see about 14MB aggregate out of a 20MB backhaul. Only P9’s and above can run ver. 8.x and above. The bonus with 9.x is you get more PPS through the link. If you have an AP capable of running 8.x (ie. a P9 or higher) you can use CNUT to change all SM’s connected to that AP to Hardware scheduling with the Advantage Platform Scheduler Tool in CNUT. That way you dont have to go SM by SM to change to HW Scheduling. Sometimes it takes a few tries to get all the SM’s changed. Once thats done you can go ahead and upgrade to 8.x and 9.x and use the autoupdate to update the SM’s. Just be sure to follow the correct upgrade path as listed in the manual (ie. 7.3.6->8.1.5.1->8.2.2->8.2.7->9.0->9.3)
We definately plan to go with the BH20 wherever possible in our system, and will evaluate the gain. We have several tests planned over the next week, and will decide on further action. Most of our APs are P8 and P7 as are our SMs. We just have a few P9 units available of any type, so going with firmware above 7.3.6 will not be possible. The P7 and P8 units have been very reliable though limited.
Thanks to all who responded!
Carol and Frank
Just FYI,
If you have the 5700BH10 as you stated earlier, setting the mode to 2x won’t increase you bandwith to 20MB, its only 2x the ‘efficiency’.
You still have a bottleneck of ~8mb aggregate.
silentsno wrote: Just FYI,
If you have the 5700BH10 as you stated earlier, setting the mode to 2x won't increase you bandwith to 20MB, its only 2x the 'efficiency'.
You still have a bottleneck of ~8mb aggregate.
AFAIK on a BH10 you do not have the option to change the modulation level between 2-level and 4-level. The area where that option to change it would be, simply says "10Mbp/second (2-level)"
Also, we run our BH20's in 50% downlink mode, and I see them starting to choke around 5-6Mbps of throughput.
What equipment are you using to convert the T1’s over the backhaul?
The T1s come into a 4 Port Card in a Cisco 7111. The wireless system shares the 4 T1s with a cable TV/internet provider. (total customer use is around 250 for both systems, 150 on the wireless side). They are the ones providing the T1s and supporting the wireless system. Most of the users go by speed tests to rate the service, which is reliably around 2 Mbps, we have seen over 4 from time to time since the addition of the 4th T1. The service is advertised as up to 3 Mbps.
We will put our BH20s back to the 20 setting on our main backhaul. We have been running them at 10 due to high jitter on that link but will try them again, and if we have the desired results we will advise purchasing more BH20 for the other main links.
Thanks to all
Carol
We have 5.7Ghz BH20’s (8.2.7) running at 20 and the jitter hits 10 sometimes but the link test are always 100% and we dont have any problems with it. We are using memory link 4-port flangers on our links that carry T1’s, but the most we have are 2 T1’s on them.
amd phreak wrote: Also, we run our BH20's in 50% downlink mode, and I see them starting to choke around 5-6Mbps of throughput.
FWIW we have a BH20 (ver 9.0 s/w) 16.5 mi. link set to 81% d/l that passes 11Mbit down/2.4Mbit up w/ 100% link efficiency. We've got 5 tower sites that pass thru that BH link, and it's solid as a rock even though it's not receiving GPS sync and using an overlapping channel. Occasionally during peak times the link is saturated. We're in the process of replacing it with a connectorized PTP58500 Lite (50Mbps).
* removed [u:pa39bz76]non[/u:pa39bz76] from overlapping.