When Alexander Graham Bell invented the first telephone in March 1876, he could hardly have conceived the impact it would have. Today, nearly a century and a half later, human beings communicate verbally using landline phones (e.g., traditional home telephone) and cellular telephones, and access data along these very same lines. Bell’s original device made use of analog technologies of the day, which was transitioned to digital transmission in the Public Switched Telephone Network (PSTN) core. Voice conversations in this proverbial world took place through a series of physical electrical circuits, thus named circuit-switched. The next progression and/or transition of telephony came in the form of packet-switched telephony, giving way to the all too familiar term VoIP (Voice over Internet Protocol). In positioning its technologies for this next-generation methodology, Cisco pioneered a number of critical elements that paved the way for practical, affordable telephony that we will examine here.
Understanding the Foundation
Cisco has classified a number of specific technology areas that require additional knowledge beyond the foundational routing and switching level itself. Each of these areas typically has additional certification requirements, normally mapping to the CCNA, CCNP, and CCIE levels. These are:
- Cisco Telepresence
- Data Center
- Optical Networking
- Unified Communications
- Service Provider
These advanced technologies carry a great deal of value in terms of employer demand and desirability, particularly if they have been paired with relevant experience. In some cases, the ability to sell and support the devices involved may be restricted to Cisco partners who possess additional certifications, usually based on staff engineering and sales roles.
You need to have an understanding of and appreciation for the critical importance of a solid network foundation and the corresponding skills necessary to support it. On a personal note, I have worked with many very intelligent and skilled advanced technology engineers who inadvertently impacted both customers and their own credibility by lacking the foundational skills referred to here.
Using an analogy in this regard, technology professionals can legitimately have great regard for the proverbial magic of the advanced technologies, and rightly so – data center, voice, security, wireless, and other areas have great desirability attached to them. Even so, each and every one of them depends directly on an optimal network infrastructure — routing and switching — in order to function at all. For example, using VMware virtualization products to simplify an enterprise data center will not produce a business/technical benefit whatsoever if the switching environment is inefficient or non-functional. Hence, if the “plumbing” doesn’t work, neither will the “magic” of advanced technologies.
Cisco carefully architected the Career Certification Program to correspond to this inevitable dependence on routing and switching technologies. In the newly announced changes to the CCNA certification, more emphasis has been placed on foundational technologies at the CCENT level, which a student must pass before moving on to the various CCNA specialization tracks. This serves as yet another reminder of the importance of knowing the fundamentals before adding on deeper skills in a particular advanced technology area.
Reproduced from Global Knowledge White Paper: Getting Started with Cisco Unified Communications Technologies.