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How Does Cisco Keep Voice Costs Down?

How does Cisco keep voice costs down with our Unified Communications voice service?

Here are six ways that Cisco IT has managed to reduce our regular telephony charges. Four of them involve doing some clever call routing – and the last two are based on some hard lessons we learned with our voice services over the years.

Tip #1: Build a simple dial plan. This will help you simplify your on-net call routing, and will build a good foundation for handling off-net call routing better, too. For Cisco IT, we mapped large blocks of 3-digit location-code prefixes to global regions, and then broke these blocks into individual number groups that were easy to remember at each of the sites. For example, to call my location near London, any Cisco user dials “8” to stay on-net, then “444” (which takes them to my Bedfont Lakes campus), and then my 4 digit extension.

(Note that as we move to SIP transport within the voice/video network, we will add SIP (URI) addresses to this, dial plan, and the CUCM will have to do translations; but we’re not there yet.)

Tip #2: Use the WAN for as many calls as possible. It’s easy to use the WAN for all on-net calls (calls that start and end at a Cisco location). It takes extra work to set up the CUCM routing configuration at each cluster to route calls destined OFF-NET (e.g. from a Cisco phone to a customer or other phone that’s not part of our WAN, but must use the PSTN). At Cisco, 45% of our calls are off-net – and most of those calls are international PSTN calls, and are usually pretty expensive. For these calls, it makes sense to route the call across our WAN for as long as possible, and then hop off to the PSTN at the tail end of the call for a local call charge. This is called tail-end hop off (TEHO) routing, and we do a LOT of TEHO at Cisco. (More on that in another blog).

Tip #3: Look for opportunities to aggregate off-net calling to a single vendor for higher discounts. Even if you can get calls to a cheaper local provider, check the tariffs per estimated traffic volume. Sometimes you can get great volume discounts that more than overcome the local distributor advantage. For example, most of our calls to European destinations go to Amsterdam gateways, then out through a SIP trunk to a single vendor; they distributes our calls from there. The calls travel longer on the PSTN, but the huge discounts we get from that provider make this worthwhile. (And it simplifies our call routing plan).

Tip #4: All the rules change in India and in the Middle East. Government-run PPTs make sure you cannot route IPT calls in ways that avoid paying long distance tariffs. There really aren’t ways to save money there, and you have to be very careful to make sure you remain faithful to the somewhat complex regulations as the price of doing business there. We have a case study that explain some of the tricks of the trade to support IP Telephony and government regulations at the same time.

Tip #5: Consider supporting both a software phone service, AND a VPN service for your employees, so they can do voice calling over VPN – softphone with software VPN, softphone or hardphone over hardware VPN. Some of our biggest phone bills came from Sales folks who used their Cisco-owned mobile devices (rather than their home or hotel phones) to make frequent, long, costly, international calls. And who could blame them wanting to avoid using their personal phone for business calls? But when we provided sales people with home teleworker VPN (using Cisco Virtual Office) with home IP phones, and those expensive calls disappeared. We also made sure all our employees had, on their laptops, a software VPN (AnyConnect) and a softphone (Jabber client) , which gives employees a much more cost-effective way to make business calls from homes without CVO, and from hotels or other places where phone calls might be expensive. So while VPN isn’t a UC service, good VPN service really reduced our mobile and hotel voice bills.

Tip #6: Last, make sure your voice service is easy to use, and service quality is high. Otherwise people will be tempted to just get an outside line and use that, or use their mobile phones for their business calls, and if they do your UC cost savings will start to disappear. We never really ran into issue, but it was something we gave a lot of thought to in the early years of IP Telephony.

Do you have any UC money-saving tips you’d like to share?

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1 Comments.


  1. Shannon Fuller

    Thanks Rich. Interesting article. I wasn’t sure what PSTN was so I had to look it up :-) Public Switched Telephone Network.

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