The Top Ten Topics You Need to Know to Pass the 70-664 Exam
Within the last ten years the business technology landscape has changed and the lines have blurred. Where there was a clear line between IT and telecoms, the two now coexist in what is now coined as unified communications. As Microsoft has been the business leader in IT communications, it has spent the last decade developing its unified communications product set. Their main offering is Microsoft LYNC, which offers a voice and messaging solution which also integrates into their existing products such as Outlook and Exchange 2010. The 70-664 exam is designed to give you the skills you need to configure a LYNC infrastructure. Having skills in unified communications is a major plus for any IT professional, so if you are looking to take the 70-664 exam you will be adding a valuable and in demand skill set to your resume. In order to assist in your studies I have listed out ten key topics in the exam that will be likely contenders for exam questions.
1. Knowledge of a Microsoft infrastructure.
When it comes to deploying any Microsoft-based software, you need to ensure that you have a sound knowledge of the infrastructure basics. By this I mean you should know how to administer Active Directory, such as creating new users and groups and applying group policies, as well as how and to what objects those policies can be applied. The DNS server is a vital role and goes hand in hand with the Active Directory. In order to ensure that name resolution is setup correctly you should be able to administer this correctly, this includes understanding the different records that can be created and the significance of the zones and their property tab settings. DNS issues can be one of the main causes of network issues so this is a key component to learn. Finally knowledge of the DHCP server is vital in a voice/LAN network. You will likely be using multiple VLANs to segregate the voice and data networks, which involves multiple DHCP scopes and settings. You should also know how to setup custom options so that the correct information is given to handsets, such as the location of the PBX or the TFTP server that is holding the correct config files.
2. Using the topology builder
You can always rely on Microsoft to supply a nice easy to deploy wizard, and LYNC is no different when it comes to beginning your first LYNC topology. As an aside at this point, the best way to learn how a wizard works is to get hands on experience using it, so lab with even a trial copy of LYNC will help you remember the steps taken during the setup.
The new topology wizard is designed to create a centralized LYNC infrastructure which contains the domain names for both internal and external access, the front end server configuration for a new pool (this is the connection point with your IP-PBX), domain permissions and file share on the Company domain for call data. On completing the wizard you can administer it using the Central Management Server (CMS). When it comes to exam questions on the topology builder, you are likely to be tested on the placement of servers in relation to the scale of the network and the location the IP-PBX. Make sure you understand that a standard LYNC topology uses a front-end server in the DMZ when interacting with the outside world and that this requires strict permission management and consideration when placing it in the infrastructure.
3. Integrating with Exchange
Ever since Exchange Server 2007 Microsoft has included the Unified Communications features. This allows you to use your Exchange infrastructure as an IVR attendant and give you the ability to send messages to users regarding voicemail and voice network notifications. This also includes the ability to make calls straight from your contacts in Outlook. When it comes to second guessing exam questions for your upcoming exam, you can guarantee these will be based on new product features or existing features that allow integration with other Microsoft applications. In short, make sure you know how Microsoft Exchange works with LYNC, how its Unified Communications features can be employed and what benefits these can add to a network.
4. Co-existing and migration from existing voice networks
LYNC is a big step forward in the Unified Comms arena, and for many, the introduction of LYNC into their business will be a cautious affair, especially when it comes to replacing the old hardwired PSTN phone systems. In order to encourage this step forward, Microsoft allows LYNC to act as a hybrid system between its VoIP and the pre-existing hardwired system. If VoIP is already in place then the migration is much easier. You are not going to be tested hard on this in the exam but expect scenarios where LYNC is being considered for an existing network and what considerations need to be made to accommodate this in terms of both your IT infrastructure and your existing telecoms infrastructure.
5. The 'P' wordPowershell in LYNC
Technical writers have been saying this for some time now with regards to Powershell, in all its forms in Microsoft: "learn it!" Trust me, if you have seen any of the new 2012 product set from Microsoft you will know that more is done with this handy scripting tool than the wizards of old and in order to get the simplest things done it is easier to fire up a Powershell command window and start typing.
So what do you use Powershell for in LYNC? Well the most common tools are those that are tedious enough that running a .PS1 file will be much easier or the commands that display information and settings while troubleshooting. For example:
Get-CsUser | Where {$_.LineURI -Like "*1740"}
This command helps find an available Direct Dial number, which is useful in large environments where users are disabled and by default there DID is kept with them and not recycled.
Get-CsManagementStoreReplicationStatus
The above command is useful for determining that all of your sites topologies are replicating correctly.
I am not saying that you will be bombarded with Powershell questions in the exam, but you are likely to get a handful of questions with multiple choice answers where choosing the correct Powershell command is a requirement.
6. High availability
In order to ensure they cover all of the bases, Microsoft exams (unless stated in the documentation) will cover a product from the enterprise level down. This is to ensure that all features and scenarios are considered. Within Enterprise environments the need for resiliency and hitting the 99.999% uptime figure requires the implementation of High Availability. Like the Exchange 2010 load balancing, you can load balance your LYNC servers. The first load balancing method is through DNS. This allows incoming SIP traffic to be distributed amongst your front end server pools and some resiliency should one of them fail. The second point of load balancing is for the web traffic going to LYNC web services; this is often managed by a third party load balancer. For the exam make sure you know how to achieve high availability and when you would need to use it.
7. Managing routing for data and voice
When it comes to managing voice and data networks, it is normally best practice to segregate these two communication methods using VLANs. The routing of data and voice is then managed by the core switch and subsequently the router for the IT comms, and the PBX for the voice comms. This allows voice traffic to get the prioritization it needs (make sure you are familiar with the term Quality of Service[QoS]) so the voice traffic is clear and uninterrupted.
Also make sure that you know the ports needed for LYNC to function correctly, as this is common ground for questions with regards to blocked communications by the firewall.
8. Instant Messaging
Instant Messaging (IM) is a useful communication tool for both businesses and socially. However, for businesses it is a key tool in reducing email overheads or text messaging costs, which are the only alternative methods of sending someone a quick message or broadcasting a communication to multiple users. LYNC IM is the central control point for all users online, since from the IM pop-up they can send an email, instant message, make a call, and display their status. If you are familiar with MSN messenger then this is very similar in its layout but with a few added features. Make sure that for the exam you have some exposure to the IM interface, you know how to apply policies which govern the recording of conversations or restricted sending, and most importantly how to setup the IM infrastructure.
9. Understanding Mediation
One of the key roles within LYNC is the mediation server role. This server is designed specifically for one purpose: transcoding known codecs and signalling to Microsoft's real time audio codec. In other words, the mediation server is responsible for translating voice traffic so the internal network can understand it. The mediation role is a lot more flexible in than previous versions and can either sit on the front end topology server/array or on a separate server of its own. Make sure you understand the role of the mediation server and can bypass it using the Media Bypass feature so that users communicate directly with the gateway for transcoding.
10. Troubleshooting LYNC
The most common errors when running any software are usually caused by mis-configuration of the application when it was installed. Microsoft knows this, and despite the easy-to-use wizard, it is still possible to enter an incorrect setting which then leads to an issue later. So in short, make sure you know the setup and configuration of LYNC well enough to back track your steps in or order to troubleshoot an issue. Once you know the installation was correct, you can use the event viewer to check for any errors that have not been flagged up by the GUI during the install. Make sure you check the Events at both the server and the client level.
There are also a number of handy resource kit tools you can use to find the root cause of an issue.
- TopologyValidator Analyzes your topology setup and validates whether or not it has been setup incorrectly or there are other infrastructure issues causing errors.
- LYNC Logging Toolused in combination with the snooper tool and assist in validating any communication errors you encounter
Outside of these tools, you may need to break down packet analysis to a finite level in order to find the root cause. Using protocol analyzers such as Wireshark or network monitor allow you to witness the communications first hand and recognise any issues on the voice or data networks.