Tag Archives: Unified Communications

Moving to Summit 7 Systems

It must be the season or something. Like several of my peers (e.g. Paul, Phoummala, and Michael, to name 3), I’m moving on from my current position to a unique new challenge. In my case, I’m taking the role of Principal Architect at Summit 7 Systems.

Astute readers may remember that, just about a year ago, I joined Dell’s global services organization as a global principal consultant. I was fortunate to work with a large group of extremely smart and talented people, including several MCMs (Todd, Dave, Andrew, Ron, and Alessandro, y’all know who I’m talking about!) Working for a large company has both its benefits and challenges, but I was happy with the work I was doing and the people I was working with. However, then this happened.

Scott Edwards, cofounder of Summit 7 and a longtime friend from my prior time in Huntsville, told me that he wanted to grow Summit 7’s very successful business, previously focused on SharePoint and business process consulting, to expand into Office 365, Lync, and Exchange. Would I be interested in helping? Yes, yes, I would. Summit 7 is already really well known in the SharePoint world, with customers such as NASA, Coca-Cola, Nucor Steel, and the State of Minnesota. SharePoint consulting is a very different world in many ways from what I’m used to, so it will be interesting, challenging, and FUN to carry the Lync/Exchange/365 torch into a new environment.

In my new role, I’ll be building a practice essentially from scratch, but I’ll be able to take advantage of Summit 7’s deep bench of project management, business process consulting, marketing, and sales talent. I’m excited by the opportunity, which is essentially the next step forward from my prior work as a delivery specialist. I am not yet taking over the role of Summit 7’s corporate pilot, but that’s on my to-do list as well. (A couple of folks have already asked, and the answer is: yes, I will be flying myself occasionally to customer gigs, something that Dell explicitly forbade. Can’t wait!)

This is an exciting opportunity for me and I relish the chance to get in and start punching. Stay tuned! (Meanwhile, you can read the official Summit 7 press release here.)


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The value of lagged copies for Exchange 2013

Let’s talk about… lagged copies.

For most Exchange administrators, the subject of lagged database copies falls somewhere between “the Kardashians’ shoe sizes” and “which of the 3 Stooges was the funniest” in terms of interest level. The concept is easy enough to understand: a lagged copy is merely a passive copy of a mailbox database where the log files are not immediately played back, as they are with ordinary passive copies. The period between the arrival of a log file and the time when it’s committed to the database is known as the lag interval. If you have a lag interval of 24 hours set to a database, a new log for that database generated at 3pm on April 4th won’t be played into the lagged copy until at least 3pm on April 5th (I say “at least” because the exact time of playback will depend on the copy queue length). The longer the lag interval, the more “distance” there is between the active copy of the mailbox database and the lagged copy.

Lagged copies are intended as a last-ditch “goalkeeper” safety mechanism in case of logical corruption. Physical corruption caused by a hardware failure will happen after Exchange has handed the data off to be written, so it won’t be replicated. Logical corruption introduced by components other than Exchange (say, an improperly configured file-level AV scanner) that directly write to the MDB or transaction log files wouldn’t be replicated in any event, so the real use case for the lagged copy is to give you a window in time during which logical corruption caused by Exchange or its clients hasn’t yet been replicated to the lagged copy. Obviously the size of this window depends on the length of the lag interval, and whether or not it is sufficient for you to a) notice that the active database has become corrupted b) play the accumulated logs forward into the lagged copy and c) activate the lagged copy depends on your environment.

The prevailing sentiment in the Exchange world has largely been “ I do backups already so lagged copies don’t give me anything.” When Exchange 2010 first introduced the notion of a lagged copy, Tony Redmond weighed in on it. Here’s what he said back then:

For now, I just can’t see how I could recommend the deployment of lagged database copies.

That seems like a reasonable stance, doesn’t it? At MEC this year, though, Microsoft came out swinging in defense of lagged copies. Why would they do that? Why would you even think of implementing lagged copies? It turns out that there are some excellent reasons that aren’t immediately apparent. (It may help to review some of the resiliency and HA improvements delivered in Exchange 2013; try this this excellent omnibus article by Microsoft’s Scott Schnoll if you want a refresher.) Here are some of the reasons why Microsoft has begun recommending the use of lagged copies more broadly.

1. Lagged copies are better in 2013

Exchange 2013 includes a number of improvements to the lagged copy mechanism. In particular, the new loose truncation feature introduced in SP1 means that you can prevent a lagged copy from taking up too much log space by adjusting the the amount of log space that the replay mechanism will use; when that limit is reached the logs will be played down to make room. Exchange 2013 (and SP1) also make a number of improvements to the Safety Net mechanism (discussed fully in Chapter 2 of the book), which can be used to play missing messages back into a lagged copy by retrieving them from the transport subsystem.

2. Lagged copies are continuously verified

When you back up a database, Exchange checks the page checksum of every page as it is backed up by computing the checksum and comparing it to the stored checksum; if that check fails, you get the dreaded JET_errReadVerifyFailure (-1018) error. However, just because you can successfully complete the backup doesn’t mean that you’ll be able to restore it when the time comes. By comparison, the Exchange log playback mechanism will log errors immediately when they are encountered during log playback. If you’re monitoring event logs on your servers, you’ll be notified as soon as this happens and you’ll know that your lagged copy is unusable now, not when you need to restore it. If you’re not monitoring your event logs, then lagged copies are the least of your problems.

3. Lagged copies give you more flexibility for recovery

When your active and passive copies of a database become unusable and you need to fall back to your lagged copy, you have several choices, as described in TechNet. You can easily play back every log that hasn’t yet been committed to the database, in the correct order, by using Move-ActiveMailboxDatabase. If you’d rather, you can play back the logs up to a certain point in time by removing the log files that you don’t want to play back. You can also play messages back directly from Safety Net into the lagged copy.

4. There’s no hardware penalty for keeping a lagged copy

Some administrators assume that you have to keep lagged copies of databases on a separate server. While this is certainly supported, you don’t have to have a “lag server” or anything like unto it. The normal practice in most designs has been to store lagged copies on other servers in the same DAG, but you don’t even have to do that. Microsoft recommends that you keep your mailbox databases no bigger than 2TB. Stuff your server with a JBOD array of the new 8TB disks (or, better yet, buy a Dell PowerVault MD1220) and you can easily put four databases on a single disk: the active copy of DB1, the primary passive copy of DB2, the secondary passive copy of DB3, and the lagged copy of DB4. This gives you an easy way to get the benefits of a 4-copy DAG while still using the full capacity of the disks you have: the additional IOPS load of the lagged copy will be low, so hosting it on a volume that already has active and passive copies of other databases is a reasonable approach (one, however, that you’ll want to test with jetstress).

It’s always been the case that the architecture Microsoft recommends when a new version of Windows or Exchange is released evolves over time as they, and we, get more experience with it in the real world. That’s clearly what has happened here; changes in the product, improvements in storage hardware, and a shift in the economic viability of conventional backups mean that lagged copies are now much more appropriate for use as a data protection mechanism than they were in the past. I expect to see them deployed more and more often as Exchange 2013 deployments continue and our collective knowledge of best practices for them improves.


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Leaving messages for non-UM-enabled users

Recently I got a good question from a coworker. He was working with a customer who was piloting Exchange Unified Messaging, and the customer was a little confused by a poorly-documented behavior of Exchange UM.

Consider that you have four test users who are UM-enabled: Alex, Brian, Carole, and David. You also have four users with Exchange mailboxes who are not UM-enabled: Magdalena, Nick, Oscar, and Pete.

The customer reported that he could dial the default automated attendant, or into Outlook Voice Access, and use dial by name to call Alex, Brian, Carole, or David.

However, he had Exchange configured to allow callers to leave voice mail messages without ringing the phone first (what I call “the coward setting”; it’s controlled with Set-UMDialPlan –SendVoiceMsgEnabled:$false). He was able to leave messages for Magdalena and the other non-UM-enabled users, which surprised him and generated the question.

This does seem odd. It’s easy to understand why you can leave a message for the first four users: they are UM-enabled, so they have extensions to which Exchange can transfer the call. But why can you leave a UM message for a user who isn’t UM-enabled? It’s because leaving a voice mail directly for a user doesn’t involve ringing an extension, so not having an extension assigned isn’t an obstacle. When you select that user for a message, UM will play the greeting (which is almost certainly going to be the system-generated TTS version of the user name, as a non-UM-enabled user probably will not have recorded a greeting) and record the message, then deliver it through the standard path.

The More You Know…


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2011 Exchange Maestro wrap-up

Greetings from high over Nebraska, where I’m aboard a Delta flight to San Francisco for a well-deserved day of rest at home (and, hopefully, a visit to In-N-Out) before heading to Vegas for Exchange Connections and then back to Pensacola.

My first visit to Connecticut was, I’d say, quite the success. We had a good-sized group of attendees, and they asked excellent and focused questions throughout. As a presenter it’s always rewarding when the audience asks questions that indicate not only that they’re listening but that they’re thinking and this group did so particularly well. That kind of back-and-forth increases the value of the workshop for everyone, and we had a lot of it.

For a first, Tony and I hit all of our timing marks until the third day! (As you might expect, I ran long on the UM content; my natural enthusiasm got the best of me.) This left the attendees more time than usual for labs, which they used to their full advantage. We didn’t have any major equipment or logistical problems; the sponsor presentations from Hewlett-Packard and BinaryTree were quite well done.

In a side note, I’m glad to report that Tony now knows what “homeboy” means in American English after discussing my PC price advantage post. He and Brian both disagreed strenuously with my assessment of the build quality of H-P’s EliteBook line, and Tony further questioned why I spec’d a 17″ EliteBook given its inconvenient size for truly mobile use– I did so because I wanted the closest match for CPU speed. In any event my admission that there still seems to be a price premium at the higher end of the configuration scale stands. Having said that, I’ve no plans to switch away from my MacBook Pro.

As of right now, we don’t currently have plans to do any Maestro events in 2012. I’m certainly open to the possibility, but we’ve had a hard time finding the optimum way to market these events and get the word out. One possibility is that we’ll work more closely with consulting and systems integration firms to go directly to their customers, and we have a few other potential tricks up our sleeves. Stay tuned for more details!

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A tricky UM routing problem

A colleague who earned his Exchange 2010 last year recently contacted me with a bit of an odd UM question. Here’s the basic scenario: Steve Secretary answers the phone for Betty Bosswoman. This was set up in Cisco Call Manager such that Steve’s phone has two extensions: 1000 (Betty’s extension) and 1001 (Steve’s extension). When someone calls Betty, both phones ring, and Steve can answer it as necessary. Sometimes Steve would answer the phone and the caller would ask for Betty’s voicemail; Steve could oblige by doing a blind transfer to Betty’s extension and the call would be routed to the voicemail system.

Things were all fine with this configuration until the advent of Exchange UM. Call answering and delivery worked fine until Steve tried to transfer a call to Betty’s voicemail, now hosted on Exchange UM. The caller whose call was transferred was getting Steve’s voicemail.. not at all the right result.

This was happening because when the call was transferred, CUCM was emitting a diversion header that indicated that the call was being sent to Steve. Why? Because Steve had Betty’s extension assigned as a secondary extension! Remember, Exchange UM uses the SIP diversion information to determine where the call’s from, who it’s to, and why Exchange is getting it. If any of these three data are incorrect or missing, Exchange will fall back to assuming that the call is to the voicemail pilot number, and you’ll hear “Welcome to Microsoft Exchange. Please enter your mailbox extension” (or whatever; the exact phrase escapes me) instead of the correct greeting.

My interlocutor wanted to know if there was a way to change this behavior on the Exchange side. Sadly there isn’t– whatever diversion header information is provided, Exchange will consume. There’s no way to rewrite, edit, or otherwise control the diversion data on the Exchange side, nor can you create rules or filters that modify the actions that Exchange takes. That’s what the call coverage map on the PBX is for, see?

Anyway, after a little head scratching, some consultation with a CUCM engineer, and the sacrifice of a chicken, it was discovered that CUCM had a way to modify the extension information sent as part of a blind transfer. The change was made so that transferring a call from Steve’s phone emitted Betty’s extension instead, and the problem was solved. Unfortunately I don’t know exactly what change was made, or I’d document it here. Such are the perils of not being a CUCM guy…


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Testing speech grammars with Exchange Unified Messaging

One of the things i teach in the MCM UM curriculum is the fact that Exchange UM has a phonetic name attribute that you can use to adjust how the system pronounces unusual names like “Robichaux” or “Szcezpanski.” MVP (and now Exchange MCM!) Jeff Guillet shared an article with me during the MCM R10 UM class that explains how to preview the pronunciation you’re going to get from a given phonetic value– I’d always done it with trial and error, but Jeff’s method is better. See Jeff’s article for background on how the phonetic system works, and learn how to preview pronunciation as a bonus.

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Exchange MCM R10 wrapup and a reminder about Exchange Maestro

Fellow Exchange MVP Jeff Guillet just finished rotation 10 (R10) of the Microsoft Certified Master program for Exchange. His writeup gives an excellent overview of what the program’s really like: intense and focused learning, now 7 days per week. It is very hard work, but the quality of the work that MCM candidates do with the skills and knowledge they get at MCM speaks for itself.

But suppose that you can’t spare the time or money to attend an MCM rotation? Good news: Tony Redmond and I have one more Exchange Maestro class coming up at the end of October in Greenwich, CT. For a limited time, using the registration code “FAN” will net you $250 off registration. (When I say “limited”, what I really mean is that I don’t know when Penton will stop honoring the code so I encourage you not to dawdle; the class is nearly full.)

But further suppose that you aren’t able to attend this Maestro event– after all, Connecticut in the fall isn’t for everyone. Good news: don’t forget that Tony and I are co-presenting a one-day workshop on planning and executing Exchange 2010 migrations as a pre-conference session at the Fall Exchange Connections show. In one action-packed day, we’ll cover the migration-related highlights from the Maestro curriculum, plus Tony will tell jokes. Trust me when I say that his jokes are not to be missed. Plus, it’s Halloween that day, so if I can persuade Tony to agree we might have a costume contest for attendees. I mean, who wouldn’t want to dress up in costume for Halloween in Las Vegas? That’s certainly on my bucket list. Feel free to leave costume suggestions for me in the comments section of this post.

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