Once the servers go off site however, the office’s connection to the Internet becomes the “weak link in the chain.” Some clients attacked that link by swapping out their current Internet connection for a more enterprise-grade connection (e.g. SDSL or bonded T-1s), but that still represents a single point of failure. Other clients upgraded their router/firewall to a device that can load balance or failover between two simultaneously active Internet connections. So when the cable modem service is down, the router automagically switches over to the DSL connection — totally seamlessly to the end users. Some router/firewalls even allow you to use one of those Sprint/Verizon Wireless PC Cards traveling laptop users have for the office’s secondary Internet connection. Which mix of redundant connections to use is a complex matter, requiring careful analysis of not only your bandwidth usage as a whole, but the workflow processes utilized by your employees, customers, vendors and others with whom you connect over the Internet, even if only by email.

As the Commonwealth of Virginia has discovered, not having any redundant Internet connectivity, even when using so-called “bulletproof” network connections, is just not acceptable. (You can read the story here.)

Consequently, we find our clients’ businesses increasingly require a conversation about the merits and costs of redundant Internet connectivity. For increasing numbers of clients, redundant Internet connectivity is no longer a luxury; rather, it is very cheap insurance if not a necessity.

If you need help deciding if redundant Internet connectivity is appropriate for your business, please feel free to give us a call at (207) 772-5678.

Mark
CIO

Your servers have redundant power supplies and with separate 30amp feeds from the two UPSs,  you carefully plug one power supply into one of the two feeds and the other power supply into the other feed.  Great, you are now protected if/when one of the UPSs goes offline.

But what about your switches and firewalls and those few remaining legacy servers, all of which have only one power supply? How can you get the benefits of the data center’s redundant UPSs and separate power feeds when you have devices with only one power cord?

Easy!  You just need a PDU (Power Distribution Unit) that plugs in to two separate power feeds, uses one feed as the primary, the other as secondary, and automatically fails over and back between the two.  Recall that we are not a reseller for any hardware or software, but we have been using the Tripp-Lite PDUMH20AT device in our own rack space now with good success.  This unit has 20amp plugs and receptacles; there is also a 15amp model.  The 20amp model costs about $360.

For really remote data center management, there is an optional SNMP card you can use to manage each of the power receptacles, program sequenced power up, etc.

Attentive engineers will note that this device introduces a new single point of failure, which is true.  Our experience however has been that data centers with redundant UPSs will, perhaps every two years or so, cycle offline the UPSs for major maintenance. Using a device like this enables your gear to stay up during UPS maintenance (or a single UPS failure).

One way to overcome this PDU’s new single point of failure, for example in the case of a pair of failover firewalls, would be to plug one of the firewalls into this device and the other firewall into one of the standard PDUs already in the rack.

Everything comes with tradeoffs, but our view is that a PDU with an automatic transfer switch represents a terrific way to provide devices with single power supplies in a data center rack the benefits from fully redundant power feeds.

If you have any questions regarding your data center configuration, please give us a call at (207) 772-5678.

But, we have seen too many companies deploy VoIP, be disappointed with the sound quality, and then face thousands of dollars of unplanned costs to make things right.  So, here is how we typically advise our clients considering a VoIP deployment:

Most importantly, whether you use a hosted VoIP solution (the VoIP servers belong to the VoIP company) or a premises-based solution (you buy, host,  maintain and life-cycle your own VoIP servers), the infrastructure challenges are the same: you need a top-notch internal network and solid connectivity to the Internet.

Internal Network Infrastructure Checklist

Look at the cabling in the wall where it comes out to attach to the patch panel, and look for the labeling on the side of the cable.  You will see something like “Cat3″ (traditional telephone patch cable), “Cat5″, “Cat5e” or “Cat6″.  Generally speaking, you’ll need Cat5e or Cat6 to have a satisfactory VoIP experience.  If you only have Cat5 cable, although technically VoIP could work, this has generally not been our experience and you should budget for new/replacement network cabling at anywhere from $50 to $150 per drop, depending on the type of wall construction and other factors.  Network cabling is a bit of a black art, so we can recommend several excellent cable installers for your situation.

If you want to have the VoIP phones share the same network cable as your PCs (the network cable coming out of the wall plugs in to the VoIP phone, and then another network cable connects the VoIP phone to the PC), you will need to have network switches that do what is called “QoS” (Quality of Service).  QoS essentially prioritizes voice traffic over data traffic, so that your call is not interrupted just because someone else on the network is downloading a big file or printing a big job.

Another term you will hear with switches is “PoE” (Power over Ethernet), which enables VoIP phones to run on power sent down the network cable.  While this reduces cable clutter on employees’ desks, PoE switches can be very expensive, and less expensive PoE switches sometimes don’t have enough joice to power all of their ports at the same time.

What many companies do who have perfectly good Cat5 data cabling in the walls is to run new Cat6 cabling just for the VoIP network.  The cable installer adds a second jack to each wall plate in every office, color coded with one color for PCs and another color coded for phones.  Since building codes no longer allow companies to abandon old network cabling in place, this can be much cheaper than doing a wholesale replacement of all of your network cabling.  And if you decide to use PoE, this separate VoIP/data network scheme can same you money on the number of new switches you need to buy.  You also don’t need expensive switches that do QoS; since voice and data are on two separate networks, there is no need to prioritize traffic.

Internet Connectivity

Regardless of whether your internal network is configured with separate VoIP and data paths, the VoIP traffic now has to get out to the phone system.  Large companies with their own VoIP servers will connect via telco drops right in their own offices, but smaller companies will generally route VoIP traffic out through the Internet.

Our experience has been that the most reliable way of doing this is to have a separate Internet connection for VoIP traffic.  How big an Internet connection is dependent on how many simultaneous calls you expect, but for a small office, a DSL connection (even with a hosted VoIP provider) often works best.

If you insist on using one Internet connection for both VoIP and data traffic, you’ll need a router/firewall that does QoS like the switches we described above, and… you’ll need to confirm with your Internet Service Provider that their network “respects”  your router/firewall QoS tagging.

Cable modems are a special case: cable modem service typically comes with a lot of bandwidth, but the operating system on the cable modems doesn’t do well with both VoIP and data traffic.  If you are using a hosted VoIP solution and have more than five VoIP phones, you will almost assuredly find you will need a separate Internet connection for VoIP and data.

Bottom Line

VoIP in principle can help companies save money, enhance productivity, and better connect multiple offices seamlessly.  But, like any house, it is only as solid as the foundation, and a VoIP system built on a marginal network backbone, or with marginal Internet connectivity will dissapoint.

Careful planning, with input from several specialists is key to a successful, cost-effective VoIP deployment.  If you would like help quarterbacking your VoIP deployment, or help deciding whether VoIP is right for your company, just give us a call at (207) 772-5678.

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