CMTS & CM

Product : CATV
Part Involved : CMTS BSR 64000
Summary: Connections involved from the HUB to the client
Scenario : Troubleshooting and following the best levels of RF
Company : ISP on Ecuador
Reference Date : August 2008.

Recomendations to follow :

- Always check the logic card configuration (domain) if this one was configured like 1x8 or 2x 1x4 and based on this will plug the test cable US / DS. For example ; talking about the configuration 2x 4x1 (with this ISP) DS0 is related to US 0,1,2,3 and DS1 is related to US 4,5,6,7, that is the downstream is loaded by 4 upstream.

- If CM was registered and this one is moved to several hubs, first connect the RF cable to CM and after that turn on it, otherwise the registration process takes more time because it is not going to find the downstream carrier will start to scan frecuencies.If CM does not get up, then check its status like as SNR levels, its probably the attenuation should be adjusted, and cables on bad states can cause communications problems between CM and CMTS

Take next as level of reference :
CMTS Tx = +55dBmV
CMTS Rx = +14dBmV (+/- 1dB)
CM Tx = 35 to 55 dBmV
CM Rx = 0 dBmV (+/- 5 dBmV)

Raid over VmWare

Product : Raid
Part Involved : Linux virtualization over VmWare
Summary: Management raid
Scenario : Testing & troubleshooting new features over linux
Company : National Institute of Cancer Sickness of Peru (INEN).
Reference Date : January 2008.

There are two videos that I have uploaded available taking this issue :
(1) Part 1 http://www.youtube.com/watch?v=gecy796j23o
(2) Part 2 http://www.youtube.com/watch?v=86n8rRyU29Y

and basically the command procedure follows the next steps :

> fdisk -l
> fdisk /dev/sdh
m (menu)
n (add new partition)
p (primary partition)
1
391 (cylinder 1-391)
p (print partition table)
L (list type of partitions available)
fd (Linux Raid Auto)
t (change system identification of partition)
L (List)
fd (Linux Raid Auto)
p (print partition table)
w (save & exist)
> fdisk /dev/sdi
> fdisk /dev/sdj
> ls /dev/md0 -l
> mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sdi1 /dev/sdj1
> mkfs.ext3 /dev/md1
> mkdir /oracle/
> mount /dev/md1 /oracle/
> df -lh
> cp /var/log/* /oracle/ -rf
> ls /oracle/
> vi /etc/fstab
** /dev/md1 /oracle ext3 defaults 0 0
:wq!

Power Off Computer
Erase disk7, disk9, disk10
Power On Computer

> df -lh
> mdadm --monitor /dev/md1
> ls /oracle/
> mkdir /oracle/hola/
> fdisk -l
** J does not have partition
> fdisk /dev/sdj
m (menu)
p (primary partition)
1-261
t (change system identification of partition)
fd (Linux Raid Auto)
p (print partition table)
w (save & exit)
> mdadm --manage /dev/md1 --add /dev/sdj1
> fdisk -l : less

Dlink & uPnP

Product : dLink DCS 2100 & dLink DI-624
Part Involved : Port 1900 (UpNp)
Summary: With no appearently reason your LAN activity has increased a burst of broadcast
Scenario : There are some delays inserted into you LAN connections.
Company : National Cancer Institute of Peru (INEN).
Reference Date : February 2008 to April 2008.

There is a hidden knowledge that is only enough to assign an ip address an every equipment connect to our LAN connections, but what happen is this device saves to itself additional functions of routing tasks when at the begining was buyed to fullfill another function ?

But it works perfectly, after your plugged it on the outlet LAN (it is sure that you are going to forget it!), and that is according to my experience in the case of this two models, but monitored with the help of WinDump application in order to identify the device connected and the ports used, when and how.

I have attached two procedures videos to detect the activity to these ports related to this issues and the later steps to disable UpNp in the device.

I sure you, that this type broadcast will not become again, at least not for this reason !

Assign IP to CISCO 2960

Product : CISCO 2960
Part Involved : Switching equipment.
Summary: Procedure of Ip configuration of switching equipment.
Scenario : Previous tasks to consider before to install switching equipment in tele room
Company : National Cancer Institute of Peru (INEN).
Reference Date : April 2008.

It is not possible to exploit the overall options of the switching equipment if this one previously is not defined and assigned the ip configuration, with this little step ensures the remote management of the equipment as the other hand you dispose : Open the conecction with the equipment to connect it by using internet explorer browser and telnet with cli commands.

As we can check, the video is based over the reviewing of the next concepts :
(1) The factory ip assigned of the switching equipment is 10.0.0.1
(2) The Pc is configured using the ip 10.0.0.200 in order to establish a connection with switching equipment.
(3) The Ip of the switching equipment is saved with the value 192.168.88.31
(4) the pc is reconfigured using the ip 192.168.88.200 with the purpose to establish connection with switching equipment and check its update of ip configuration.
(5) Check the video to confirm these steps.

! Remember, if you you do not proceed with the change of ip address of every new switching equipment you can crash your LAN connections because there are ip conflicts !

Later in another articles, I will take some ways to show you How to catch up some troubleshooting issues linked with this issue.

Handing RJ45 Jacks

Product : RJ45 Jacks connectors over cat6.
Part Involved : Infrastructure of telecomunication room.
Summary: Management the ending of the horizontal cabling inside telecomunication rooms.
Scenario : A burst growing of the LAN data ports in your company.
Company : National Institute of Cancer of Peru (INEN).
Reference Date : April 2008.

Although add new data ports to the current structured cabling involved civil works in order to tending the cable, then another bottleneck does not consider the most time is the distribution of the space inside of the telecomunication room. Check with the next video , how the ending cable cat6 is not easy to hand -the cable is not soft, can be damaged if there is no previous precaution during tending task - and when this point is reached certainly the personnel assigned to this job come very dirty.

It is important to clear that pin wire assigned color of RJ45 jack connector of the telecomunication room should be fix with the RJ45 jack connector of the outlet box (office) assigned to that cabling connection.

The first part of video shows the procedure to insert the wire into RJ45 Jack connector following the color code based on Code A or Code B -assigning the same to telecomunication room and office- and put the connector inside of the patch panel, while the second part is focused on the front view of the telecomunication room to connect the patch cord from the patch panel port to the free switch port.

The full version is available on "YouTube videos hosted by German Medina" at the bottom right side of this page.