Hi group
We recently purchase another cmts (bsr2k) due to our old cmts (a bsr1k) is becoming too small for our users. What I want to do is to separate the traffic between the two cmts and to split the users for differents upstream ports.
We use ISC dhcp and on the dhcpd.conf we declare the file for the users. Is on this file where we indicate which upstream port to use through the cable modem file and the tftp. But if I add another cmts with the same number of ports, how can I make the difference on the dhcpd.config to use one cmts or another? Do I have to use one dhcpd server for one cmts and other dhcpd server for the second cmts?
Thanks in advance
If I understand your questions correctly the correct approach is to configure and use a different IP scope for the other CMTS, no need for a second dhcp server. The server will respond to the discover and offer an ip address from the correct scope.
Hi group
Sorry, I'm not clear
Sorry for my english ;-)
I have this on my dhcpd.conf
#######
group {
next-server xxxx.xxxx.xxxx.xxxx;
filename "256up_256down__canal0_4pc.cfg";
##
This is the part ("__canal0...") "channel 0 in English" where I tell to cable modems from an area "look! go to upstream port 0/0" throught the filename. And so on in the following statements in the dhcpd.conf.
So if I have another cmts working with the same 4 upstreams ports with the same numbers of ports (0,1,2,3) the true question is how can I declare in my dhcpd.conf the difference between the upstream port 0 from cmts A and upstream 0 from cmts B if they are the same? Is here where I have to use two differents dhcpd servers?
Thanks in advance!
I understand what you are doing, i just dont understand why. And I also see the problem involving using a second cmts.
First, the upstream from a particular area should only come back to one physical upstream port. Is there a reason why you have it cabeld back to multiple receiver ports? Is there only one physical return that you have split accross all the upstream ports?
Can you send me the entire dhcpd.conf file to proairpass@yahoo.com
Hi mtntrailseeker
I'm going to send you my dhcpd.conf. The why? well is a long story....
We have multiple problems with one specific area. What we want to do is to split the optical node because there are many users plugged to that node. We still thinking which are the components necesary for that. When we are capable to do that well we're not going to have an available upstream port for those who have been splitted once that process is over.
So we need the second and brand new cmts ;-) for adding more upstream ports. That's why I'm trying to find out how to put the two of them working together. One optical node for each populated area from our city goes to one upstream port in cmts.
I will send you my dhcpd.conf for your help
Thanks! for your help
It's done!
Thanks!
I didn't see the reply to mtntrailseeker's question on how the return is combined going to the receivers, but rather than force a modem onto a given upstream port, you could balance between two or more recievers. that would be a better option should you have a return problem on a given freq or channel because the modems would move to the other port and service would not go down.
Hi cmcaldas, thanks for your post
Mr. Mtntrailseeker is helping me throught this process. I will explain you the overview of our network. Well, we have 4 optical nodes on the city and each one of these goes to one upstream port. I know that we use "combiners" (I don't know the full HFC expression, I'm not an HFC expert) for TV and Internet. Sorry for my little understanding, but I think that when you're refer to "receivers" you mean to the optical card or the upstream port from cmts?
What we have is optical cards which "iluminates" the different optical nodes. What we're trying to do is to split one optical node which is overloaded from an specific area. To do this we need to configure our Harmonic optical node. But we don't know hot to do it.,,
So, how can I load balance on my cmts? we have a BSR2k. Is trough HFC plant or CMTS commands?
Thanks in advance! !!
Mtntrailseeker, is that you Tom S?
IF you have nodes that go to a given upstream port on the cmts, then you don't need to have a modem file that says modem xxxx.xxxx.xxxx use upstream port 0. it can only go to 0 anyway. now the load balance would use two frequencies or channels. you would combine two nodes, let's say the one with lots of modems and another with just a few modems. you need to keep an eye on the signal to noise.
create a spectrum group and have it wider than the two channels you use and then apply it to the two receivers, example 0 and 1.
here's a part of what it should look like: note that upstream port 0 and 1 have the same spectrum group. so if I have 400 on one port and 200 on the other, it would move some so it's 300 and 300. so a modem that gets a file to go to a given upstream port would have problems to register. but should something happen to port 0, the modems would stay online with port 1
cable spectrum-group group1
band 5000000 42000000
load-balancing static
cable upstream 0 physical-delay automatic
cable upstream 0 spectrum-group group1
cable upstream 0 rate-limit
no cable upstream 0 shutdown
no cable upstream 0/0 shutdown
cable upstream 0/1 channel-type atdma
cable upstream 0/1 shutdown
cable upstream 0/2 shutdown
cable upstream 0/3 shutdown
cable upstream 1/0 channel-type atdma
cable upstream 1 channel-width 6400000
cable upstream 1 pre-equalization
cable upstream 1 physical-delay automatic
cable upstream 1 spectrum-group group1
cable upstream 1 ingress-canceller enable
cable upstream 1/0 range-backoff 2 8
cable upstream 1 map-interval 2000
cable upstream 1/0 modulation-profile 255
cable upstream 1 rate-limit
cable upstream 1 snr-offset 10
no cable upstream 1 shutdown
no cable upstream 1/0 shutdown
cable upstream 1/1 channel-type atdma
cable upstream 1/1 modulation-profile 255
no cable upstream 1/1 shutdown
Hi cmcaldas
That's what I need it! Let me some time to try it. That's a very good example.
I will let you know my answers
Thanks! for everything
Hi cmcaldas
I made the changes. This is what I did:
!
cable spectrum-group combinado
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
load-balancing static
!
cable upstream 0 frequency 33000000
cable upstream 0 spectrum-group combinado
cable upstream 0/0 range-backoff 2 8
cable upstream 0 power-level 80
cable upstream 0 rate-limit
no cable upstream 0 shutdown
no cable upstream 0/0 shutdown
no cable upstream 0/1 shutdown
cable upstream 0/2 shutdown
cable upstream 0/3 shutdown
cable upstream 1 channel-width 1600000
cable upstream 1 frequency 33000000
cable upstream 1 spectrum-group combinado
cable upstream 1/0 range-backoff 2 8
cable upstream 1 power-level 80
cable upstream 1/0 modulation-profile 2
cable upstream 1 rate-limit
no cable upstream 1 shutdown
no cable upstream 1/0 shutdown
After made those changes, I saw nothing change. But when we wanted to put to work a new cable modem on port 0 this is what I got:
cmts2#show cable modem 001a.de74.5486 hosts
Interface Prim Connect Timing Rec Ip Address Mac Address
Sid State Offset Power
Cable 0/0/D0/U0/C0 2518 online 2303 8.0 10.0.4.173 001a.de74.5486
Number of Hosts = 0
cmts2#show cable modem 001a.de74.5486 hosts
Interface Prim Connect Timing Rec Ip Address Mac Address
Sid State Offset Power
Cable 0/0/D0/U1/C0 2518 online 2303 8.0 10.0.4.173 001a.de74.5486
Number of Hosts = 0
cmts2#
Effectively that cable modem belongs physically to port 0 but after a few seconds went to port 1 and the cable modem (a SB5101 motorola) stays in led send blinking.
This is the output
cmts2#sho cable ucc-stats
CMTS Slot: 0 MAC Domain: 0 Interface index: 8323072
Number of UCC Reqs : 3
Number of UCC Rsps : 3
Number of UCC : 3
Number of UCC Fails : 0
cmts2#
Is there something wrong? Do I have to change the modem file in order to remove the Channel ID so he could discover by itself?
Thanks in advance!
you can't have upstream 0 and 1 on the same frequency.... if you recall in my post, you need two channels or frequencies and remove from the modem file the section that tells the modem to use a given upstream. if the cmts tells the modem to move and the modem file says to stay or only register on upstream 0 for example, it won't stay online when it moves to upstream port 1..
also, why is the channel width less on upstream port 1 than 0? they should be the same
Hi group
Hi cmcaldas
Ok, please let me a few days to make all necesary changes because I've been a little bit busy with another issues. I will let you know. Thanks for your patience and your time
Bye
Hi group
Sorry for my late post. I've been working not closely as I want for this issue.
Hi cmcaldas. As you will see next I'm trying, and trying but I still haven't found what I'm looking for...... (U2 :-)
I did changes on the cmts. I changed frequency for upstream port. For up 0 the freq is 330 and for up 1 is 360. When I add the same spectrum group parameter (called "combinado") for up 0 and up 1, cable modems stays on send blinking and it goes from up 0 to up 1 on the cmts. This is my config.
!
cable spectrum-group combinado
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
load-balancing static
!
cable cmts type domestic
!
cable spectrum-group grupo0
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
!
cable spectrum-group grupo1
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
!
cable spectrum-group grupo2
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
!
cable spectrum-group grupo3
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
!
cable spectrum-group combinado
band 23000000 40000000
hop action frequency 36000000 priority 2
hop action roll-back
load-balancing static
!
cable downstream 0 modulation 64
cable downstream 0 power-level 500
cable downstream 0 rate-limit
no cable downstream 0 shutdown
cable upstream 0 frequency 33000000
cable upstream 0 spectrum-group combinado
cable upstream 0/0 range-backoff 2 8
cable upstream 0 power-level 80
cable upstream 0 rate-limit
no cable upstream 0 shutdown
no cable upstream 0/0 shutdown
no cable upstream 0/1 shutdown
cable upstream 0/2 shutdown
cable upstream 0/3 shutdown
cable upstream 1 channel-width 1600000
cable upstream 1 frequency 33600000
cable upstream 1 spectrum-group combinado
cable upstream 1/0 range-backoff 2 8
cable upstream 1 power-level 80
cable upstream 1/0 modulation-profile 2
cable upstream 1 rate-limit
no cable upstream 1 shutdown
cmts2#sho cable ucc-stats
CMTS Slot: 0 MAC Domain: 0 Interface index: 8323072
Number of UCC Reqs : 576
Number of UCC Rsps : 572
Number of UCC : 572
Number of UCC Fails : 1
cmts2#
As you can see we have different frequencies on the upstream port. And config files are now opened (there's no channel ID parameter enabled).
The SNR seems to be fine after the changes. And the ucc-stats show me that cable modems goes from one port to another. But doesn't get online.
What else could be?
Thanks for your post!
PD: You asked me for the channel witdh. We have different channel witdh because we use different modulation profile for upstream 0.
Question on the modems, what version docsis are they and the command shows that one modem failed. you can email me a show tech or email me telnet access to go in and take a look around. promise to not change things ;-)
Hi cmcaldas
I will send you the show tech output. There's many docsis versions for cable modems. Some are in 1.1 and other 2.0 and 1.0. Is possible that LB not working for different modulation profile on the up 0 and up 1?
Thanks for your post.