Business trends of today seem to be a "Unified Network" this means that we bring together data, voice and video on the same network. With the technologies available this is plausible. We can save a significant amount of money by intergrating VOIP to our network. It's simply in some cases running another VLAN on the switch (2 switches in 1!). Also business seem to be having this buzz word "Cloud Computing" all well and good till you lose you internet connection and you don't have access to these resources, so building a redundant topology comes into play in the design. Also discussed in the book is a thing called Borderless Networks Architecture where we can have a worker at their own home or on the road have access to network resources (shared drives, intranet and voice calls). Identifying what is critical to the business.
When we design a network we need to know what requirements are needed, do we need a backup internet connection? Do we need QoS on our VOIP calls? Does a certain bit of software need reliable fast throughput to the servers?
Now for network auditing tools to help in characterizing the network there is a range to chose from. Some vendors have their own and there are 3rd party tools as well. (I don't know alot in this area so feel free to add in). The main ones I keep seeing come up in my studies are NetFlow and NBAR, these tools analyse traffic flows and give details on application ports (anyone used these before? give us some more info?)
Also existing documentation (if there is any =P) can be helpful in auditing the network. I'm sure we've all been there when there is jack all doco or it hasn't been updated for 10years (gotta love it).
The top down approach for network design is essentially refering to the OSI model, come on now we should know this off by heart. Application, Presentation, Session, Transport, Network, Data Link, Physical. We seperate these into two where we define the requirement of the upper layers (Application, Presentation, Session) which to me appear to be software or services like voice and video. And then we define the infrastructure for lower layers (Transport, Network, Data Link, Physical) so we design the infrastructre around the applications. So we may want have QoS on our VOIP transport or we may engineer network traffic to transport data over a certain link thats faster and reliable. It's pointless if we design from the bottom up because we can run into challenges where the infrastructure doesn't allow for a certain application or service because we were ignorrant to the requirements.
One management protocol that comes to mind is SNMP (Simple Network Management Protocol). SNMP is used to report information to a controller, it's quite useful in managing a network where we can recieve alerts if a port goes down or we are getting a lot of Transmit and Recieves on a certain link. It can be configured for certain information but I'm not familiar with this and struggle to discuss this but theres a whole chapter from memory about it in our books. Definately worth a read and one to research further out of interest.
Business trends of today seem to be a "Unified Network" this means that we bring together data, voice and video on the same network.
Not quite, that business trend was back in the 20th century (over 10-years ago) and the term used to describe it was 'Convergence', with Cisco introducing their 'Architecture for Voice, Video and Intergrated Data' (AVVID).
I think today you'll find the main business trends they're referring to are Data Centre Virtualisation and Cloud Computing, with the 'Unified Network' referring to Compute, Network and Storage, not VoIP!
Unified Networking to me is a marketing term and I have seen sales people refer to both the 20th century definate as rmhango calls it and the 21st century defination as more of the cloud concepts.
As for the purpose of the CCDA, lets break down the objectives listed above. I am looking in my CCDA Official Cert guide in Chapter 1 and the first topic is "Cisco Architectures for the Enterprise" The title in and of itself says alot. Let's discuss Cisco's arcitectures for Enterprise design.
Now the book refers to 3 distinct architectures.
Each of these would have its own design guidelines, challenges and technological focuses. If you look on the certifications page of CLN, you will find that Cisco's certs all correspond to one of these 3. Now there are other architectures's but for the CCDA, we are going to only focus on the Enterprise.
So, lets start out by talking about these 3 architectures and how they fit into Cisco's vision of the enterprise.
That was the intent because there was a quick spike in CCDA activity, but it died as fast as it grew. CCDA is one of my many interests so I was just trying to get something going when I saw that CCDA activity grow.
Thanks for trying to promote this. I think having good detailed discussions could really help candidates pass the CCDA.
I think a lot of people look at the CCDA and go "I want to learn how to design!!!". The CCDA is just the entry level - it's not how to design, it's the basic foundational concepts that you need to have to start building your design skillset.
A lot like ITIL - nobody wants to do the foot work to learn it, but everyone loves the benefits once someone in your organization can do it.