This is great news on a long overdue feature. If you’re fortunate enough to manage a tight ship with regard to AD then you may have never had the need to restore a deleted object. In the pre-2008 R2 world if you did need to restore a deleted object then you were looking at an authoritative restore via Directory Services Restore Mode. In 2008 R2, deleted objects go to a new hidden container called “Deleted Objects”. This feature is not enabled by default but can be turned on by raising the forest functional level to 2008 R2 and by running a PowerShell script from the Active Directory Module for Powershell. For ease, import the AD cmdlets into PowerShell first by running:

Then to enable the feature (replace contoso with your domain name):

Enable-ADOptionalFeature –Identity ‘CN=Recycle Bin Feature,CN=Optional Features,CN=Directory Service,CN=Windows NT,CN=Services,CN=Configuration, DC=contoso,DC=com’ –Scope ForestOrConfigurationSet –Target ‘contoso.com’

Restores can occur via PowerShell or LDP. Via PowerShell:

Open the Active Directory PowerShell command Prompt and use the following syntax: Get-ADObject -Filter {displayName -eq "Brian"} -IncludeDeletedObjects | Restore-ADObject

Recycling Active Directory Trash [Life of Brian], [Technet]

One of the advantages I have in my current job role is being able to research, test, and deploy all facets of enterprise technology. I am by trade a “server guy” but I have some fairly extensive experience on the network side of things as well, L2/L3 switching and firewalling mainly. I have had VOIP running at home for many years now and did a very small implementation for a startup years ago. This is my  first enterprise installation.

Call Managers

The two top contenders in the enterprise voice world are Cisco and Avaya. People swear by each, it depends who you talk to. My perception is that Cisco is the “Cadillac” option and there’s a saying in IT, “No one’s ever been fired for buying Cisco”. While both vendors have similar offerings and options with regard to call managers and IP phones, Avaya is typically cheaper all things considered. I’m building out a brand new datacenter infrastructure as part of my efforts which means I need new switches and firewalls. This is where the Cisco voice option makes the most sense. Serious discounts are to be had by buying voice gear bundled with core infrastructure. Cisco is very serious about not losing out on voice deals and make it very hard for competitors while pricing new build-outs.

Cisco has four essential options when it comes to voice platforms, all falling under variations of the moniker Cisco Unified Communications Manager. I’m still partial to Cisco’s original product name Call Manager, but I digress. CM can be purchased as:

• Express (CME)
• Unified Communications 500
• Business Edition (CMB)
• and full blown Communications Manager (CM)

Here is the  short take on the differences: CME is a voice enabled router with a CME vWIC (add-on card). The basic CM functions are handled but this solution is intended for very small environments. UC 500 is a stackable appliance that tops out at 64 phones. CMB is a hardened appliance (an OEM’d HP DL320 painted Cisco teal) that is capable of running the full functionality that CM can offer but is locked to a single appliance. This level in particular has a leg up on Avaya as CMB contains the Unity Connection voice mail system baked into the appliance. Avaya’s comparable IP Office product requires a separate server to handle this function. Full blown CM has the same essential feature sets as CMB but it can be run on various “Media Convergence Servers” (MCS) that vary in specs, and it’s clusterable. The CMB appliance is based on the MCS 7828 platform.

Getting to the PSTN

We have a few options when it comes to providing connectivity for our voice services. Yes VOIP is voice over IP but this does not mean you can simply run it over your main data circuits like you do your Vonage service at home. Telephony is an important aspect of business operation and not only deserves a dedicated solution, but requires it. There are two primary means for connecting to the PSTN (Public Switched Telephone Network), PRI and SIP.

Primary Rate Interface circuits (PRI) are channelized versions of traditional T1/T3 type circuits. A T1 contains 24 channels, 23 of which can be used for placing calls, the 24th is used for signaling. Oversubscription is common and practical so for architecture purposes you have to consider how many simultaneous outbound calls your environment is likely to experience. Internal calls are switched through CM and do not cross the PRI. So for 100 users you could probably safely plan for the likelihood that 40 people might be on the phone at once. Call centers would be thought of differently, obviously. To satisfy those 40 calls, however, you will need 2 PRIs (T1’s).

Session Initiation Protocol (SIP) is purchased as a “SIP trunk” which is an IP connection that permits voice traffic to be routed over the backbone of the carrier. The advantage of SIP is that it’s purchased by bandwidth increments (3Mbps, 5Mbps, etc) which can be increased easily and is normally cheaper than an equivalent PRI. It can also be used for voice and data traffic. The same basic principle of the PRI applies to SIP when planning for oversubscription. 1 x PRI (1 T1) = 1.5Mbps so 1 x 3Mbps SIP trunk is equivalent to 2 x PRI’s.

Voice experts that I’ve spoken with at Cisco and Avaya still think a pure SIP solution is too immature today in terms of call quality. Both recommend at least a partial PRI solution for primary calls and leveraging SIP for call spillover/ redundancy. I’ll go into this deeper in the design. Another important consideration is to ensure that the voice carriers are the same for SIP/PRI, especially between sites. If different carriers are chosen and the primary circuit fails, carrier B would not be set up to receive calls for the company’s DID’s (phone numbers).

Design

My design consists of a two-phase approach providing primary voice services for a main campus location, with acceptable levels of redundancy, for phase one and DR voice services for phase two. Cisco guarantees a 4-hour response time but we can’t have a 4-hour voice outage. Of the choices available CMB makes the most sense for my design. I need to connect 100-125 phones, sustain at least 40 concurrent outbound calls, and, barring facility complications beyond my control, guarantee 99.9% onsite uptime. CMB is a feature rich appliance with redundant hardware features and carries a price point that fits my budget.

For onsite redundancy with CMB there are three viable options.

• Cold spare appliance
• SRST-enabled router
• CME-enabled router

Configs can be backed up and imported into a stand-by appliance which is fast and easy from a recovery stand point. The problem is that this solution isn’t cost effective. Survivable Remote Site Telephony (SRST) can be leveraged in a number of ways. It can be used to provide high availability for the main campus or to protect branch offices from a CM failure in the main campus. Connected IP phones will register the SRST router as a call processor so if there is a problem with CM, SRST will take over telephony operations seamlessly. Functionality is reduced to basic call processing in SRST mode but that is what’s most important after all. CME is also a viable option but isn’t as cost effective as SRST.

Sizing your main campus SRST router is important to ensure that it can sustain the same level of calls that CM did. For my design I’ll be using a voice-enabled 2851 router for the main campus. For DR considerations you can’t have a remote SRST router handling calls for the main campus in the absence of CM, this is a per site limitation. To provide that level of redundancy we would need to deploy another CM in DR. For my DR purposes I can deploy a smaller (cheaper) 2801 router which will serve as a voice gateway for CM in the main campus. What this design buys me is network redundancy should something happen to my 2851, PRI, or SIP circuits in the main campus. CM will route, via IP, to DR and use the SRST router there as the gateway to the PSTN. Budgeting prohibits me from making my design completely bullet-proof so I have to account for as many scenarios as I possibly can.

Leveraging both PRI and SIP circuits in the main campus accomplishes three things. Should the PRI circuits fill up, i.e. caller 47 picks up the phone, this call would be routed out the SIP trunk. Should the PRI circuits fail for any reason, CM will route calls out the SIP trunk for the duration of the outage. Should the primary internet data circuit fail, the SIP trunk will serve as a backup for internet access.

My architecture will satisfy the following objectives:

• HA for CMB in the main campus via SRST
• Redundancy for main campus voice circuits via deployment of PRI’s and SIP
• DR to protect against main campus PRI, SIP, or SRST router failures

I will talk more about switching, security, IP phones, and data circuits in part 2 of this topic. Here is a high level view of my overall architecture:

I was digging around in a couple of my Server 2008 VMs looking to free up some space and noticed hiberfil.sys in the root of C. If you’re not familiar this is the file created by Windows for the hibernation feature. Although hibernation is disabled by default in Server 2008, if your server has less than 4GB RAM hiberfil.sys is still created in the case of power failure. This is by design. If you want to reclaim this precious space you can kill the file by running the following from the command line (there is no GUI alternative): powercfg /hibernate off

Link 1: http://support.microsoft.com/kb/920730/

Link 2: Feature confirmed as by design

In my experience, most companies run either Dell or HP servers. The predominant choice for those that choose HP is the popular volume commodity Proliant platform. Server burn-in is a topic that comes up occasionally with some shops skipping it completely and others wanting to do something but not knowing quite what to do. One could use popular desktop stress testing products like Prime95 or SuperPi that stress CPU and RAM primarily. Sandra from SiSoftware, another popular desktop benchmarking suite, can be purchased in a very expensive enterprise platform, but there is an easier way to ensure your new Proliant server is production-ready.

Many don’t realize that HP has some great tools bundled with their Smart Start suite for free! HP Insight Diagnostics is all you need to confidently test and burn-in your hardware. As a matter of good practice, before you turn your new server over to the production world of your company to be entrusted with tasks, critical in nature, you should thoroughly test the hardware. All of it! From the CPU to the PCIe slots, fans, power supplies and everything in between. Sandra is capable of running specific benchmark and diagnostic jobs targeting elements of specific components, but can it run exhaustive read tests against every PCI slot in the server? Exhaustively test the cache of each CPU in an MP server? No.

Insight Diagnostics can be run in two modes: Offline or Online. Offline tests are far more broad and granular than their online counterparts. Screens below show a few of the components that can be stressed and evaluated in this mode. Online mode, accessed via a running Server’s System Management Homepage (servername:2381), is far more limited providing diagnosis only for Smart Array volumes and supported power supplies. Online diagnostics can be run without disrupting active server operation.

To get started in Offline (burn-in) mode, boot your server with the latest Smart Start CD (or attach the ISO via virtual media in iLo) and enter the “maintain server” menu. Launch the diagnostics option and click the Test tab. Here you can choose specific devices you want to test or just simply choose all. Every single component of the server can be exhaustively tested. Then set the number of loops and maximum test time. 1 full loop on a 5th gen DL380 will take over an hour. I’d run this on a new server for at least a few hours up to a day or 2 if you have the time. If all tests pass on all components then you should feel confident that your new hardware is ready for production.

If you are about to purchase a 5th gen Proliant server that you intend to install Server 2008 x64 on, I want to save you a bit of trouble. Whether you image the box or build from scratch with SmartStart, if your BIOS rev is P56 2008.08.03 or earlier, once you get to the GUI portion of the setup you may get the following blue screen.

This will happen if you’re running dual or quad core Xeon CPUs that are different revisions. If your procs are identical then you won’t see this problem. This issue is fixed in the HP BIOS P56 2008.09.29 or later. Grab the firmware maintenance image from hp.com, connect via the ILO’s Virtual Media applet, and upgrade to the latest rev.

How about $0.81 for a 2M (6-ft) cable? For less than 5 bucks shipped you can't beat this and the multitude of reviews are glowing. The debates will go on forever but digital is on or off and if this cable delivers the signal then yipee. Made in China but come on...