Digging deep into Unified Communications from Spain.

Campus infrastructure and QoS

July 7th, 2012 | Posted by Jaime Diez in Cisco - (0 Comments)

During these last two weeks I have been dealing with the campus infrastructure, VLAN, DHCP, TFTP and NTP, brushing up on some concepts, and also with QoS, which has taken me most of my time. QoS was the topic in which I had the less experience, but now, I can say that I understand it and know how it works perfectly.

In this post I will just show you the guides and documents that I am using. Next week I will post again with some examples and notes.

Regarding VLAN, DHCP, TFTP and NTP protocols, if you are pursuing the CCIE Voice, like I am, you should be quite familiarized with these, but it is worth it to have a look at the SRND to refresh best practices

Cisco SRND CUCM 7.x

Try these links in case you need to check any example, commands, or ways to configure something:

Cisco IOS 12.4T

Catalyst 3750 12.2(44) Configuration Guide

Catalyst 3750 12.2(44) Command Reference Guide

Regarding QoS, you should read the following to get the expert level:

Cisco SRND QoS

QoS section in the Catalyst 3750 Configuration Guide

QoS section in the Medianet Reference Guide

Cisco QoS Command Reference

Here you have some useful examples:

Cisco Catalys 3750 QoS configuration examples

In the following link, you can see an animation to make understanding easier.

QoS animation

In a lab environment sometimes is difficult to simulate congestion, therefore you have better know the behaviour of every command that you type because you will just be able to “test” it in your mind.

I also have been watching some videos which have been really useful to learn some tips and new ways to do things.

This is a short post but deep in content.

In previous post, I expressed my desire to get the CCIE Voice certification, so because I am going to start my continuous working day at work(not stopping for lunch), I have been preparing and scheduling my “journey” for the next months. I know that the version could change soon, but I am not in a hurry. The five numbers are the prize, but the important part is the knowledge.

There are no guides or specific books to get this certification, just the blueprint with the topics that will appear on the exam. It requires the best of your effort and proper planning. Every person is completely different, so something that worked for one might not work for others.

To accomplish my goal, I have designed my schedule based on my personality and the things that I have learnt about myself. Nobody knows you better than yourself. Look inside of yourself and look for your most productive hours and days. how will you handle difficult moments when you feel down (because you will have these)? On the other hand, when you feel full of energy, how will you take advantage of that?
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Changing the IP for a CUCM cluster

June 18th, 2012 | Posted by Jaime Diez in Cisco - (0 Comments)

Lately I have had to change the network parameters for a CUCM cluster, this is not a day-to-day task, because of that I going to show you how to change it to avoid any major issue.

As a network parameter, it should be done during a time window out of business hours. As you would do with any other operation, verify the proper operation of the CUCM cluster before make any change, make a backup and have a rollback plan to use in case that something goes wrong.

You will find a guide from Cisco which is a good point to start and covers all the process but I like to have always my own documentation in addition to other, to have my own notes. It helps me to remember important details and issues that I have had, the purpose is to have the whole experience write down.

Let’s start the task, it is very important to follow this order to avoid any error. You will have to request a new license file re-issued  by Cisco to use it after the change. Start making all the changes on the publisher and after that with the subscribers.
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As promised in previous entries, I am going to explain to you my Cisco lab environment. It could be useful for hundred of purposes, to prepare for your studies, to practise for your CCNP Voice or CCIE Voice certification or just to make tests. Despite the fact that it covers a wide range of topics in the CCIE Voice lab, it doesn’t follow the common topology with three sites.

I built it bearing in mind the CCIE Voice lab, which I would like to get in the future, but since I noticed that the new lab version is coming and that I wasn’t able to dedicate the require time needed in the short term (2-3 months), I decided to stop buying new devices and see what  will happen, however all these things are time consuming!

First of all, below you can find the network diagram which I have deployed.

Cisco Voice Environment

Hardware list

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I can say that my ESXi server is the heart of my lab, so before I got everything, I was doing some research to get the best deal. The easiest way to get it built, is to follow the VMware hardware guide to get a supported server, but it means a higher price and maybe, pointless features for our purpose like redundant PSUs. On the other hand, you will, unlike me, save some headaches with the supported path. I like challenges!

In my case, I wanted something small with support for VM Direct Path and of course, all the hardware embedded on the motherboard. Based on those prerequisites, I found the Asrock Z68 Pro3-M, a micro-ATX form factor motherboard.

Hardware list:

– Motherboard: Asrock Z68 Pro3-M (Graphics and NIC on-board)

– CPU: Intel Core i5-2500 (note that is the non-K version, to take advantage of the virtualization features)

– RAM: 4x8Gb G.Skill Ares

– Case: Cooler Master Elite 342 MicroATX

– PSU: Tacens Radix V 450W

– HD: 1x Samsung SSD 830 128Gb – 4x2TB Seagate ST2000DL003

– Extra: Intel pci NIC.


I boot ESXi 5.0 from a USB pen drive and without doing anything, everything is recognized, the NIC Realtek RTL8111E included.

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