Objective measures - consulting for fixing a "broken" VoIP deployment

Hi, everyone,

I have a question related - mostly - to consulting services, and possibility of matching requirements against some industry benchmarks, for which I have no prior experience:

Problem: deployment of a Cisco Call Manager Express + Unity Express, in a location with approximately (initially model 7912) thirty phones. Ever since installation we have experienced problems which led to the replacement of all phones (with new models - 7960s, then 7940s), routers (1760 and 2600) with a 2821 and interfaces, lines with the provider, the Unity hardware, etc.... - and still not working right.

Issue: due to lack of in-house espertise, we would like to bring in outside consulting services (other than the ones which got us here, of course).

Question: what kind of "verbiage" could one add to a contract, that would tie the resolution of open problems ("hollow" echo noise, internally and externally, low voice volume, failure of auto-attendant scripts, etc.) to industry standards, or - differently asked - could someone point me to OBJECTIVE measures that could be part of a contract, in regards to voice "quality", level of performance, etc.?!?

TIA, Papi

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Hi Papi,

Suggest you contact Jim Berbee ( who earned Cisco's 2003 U.S. Partner of the Year Award ), let Jim know Brad Reese suggested you contact him:

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Berbee's IP Telephony team:

A very skilled voice team, experienced in planning, designing and implementing voice projects, evidenced by more than 40,000 phones and

3000 call center agents for multiple national sites across 200 clients.

Berbee's custom-developed IP Telephony applications, sales of which have reached over 250,000 seats worldwide.

Deep expertise Cisco's IP Contact Center solutions.

A skilled operations team which supports our installed base of customers.

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Brad Reese BradReese.Com Cisco Repair Worldwide United Kingdom: 44-20-70784294 U.S. Toll Free: 877-549-2680 International: 828-277-7272 Fax: 775-254-3558 Website:

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I hope you don't mind but I'm going to flag your post and save it in my own archives to share with future "would-be" Cisco VOIP buyers.

Honestly, without being able to perform a site survey, it's going to be a lot of guesswork and pure conjecture as to the root cause(s) of your plight. Sounds like several problems at work here, all the work of or rather result of poor engineering. Echo (hollow-sounding audio) is usually indicative of a level problem and/or impedance mismatch where the call transitions between the VOIP interface and the analog outside world. Turn it down!!

If you're attempting to integrate your voice traffic into your existing data network, you've generally got to use layer 2 Etherswitches that perform VLan tagging and 802.1p/q quality of service. You create virtual lans, effectively separating the voice and data traffic onto separate VLans with the voice traffic having priority. If you have any VOIP phones or VOIP circuits running through hubs, gather up all of the hubs and take them over to your nearest readi-mix plant. I'm told these places use them for driveway fill and wheel chocks for their concrete trucks. ;)

Auto-attendant scripts failing sounds like a voicemail application problem. There are only a few very good voice mail systems out there. All the rest are wannabes. IMO Unity VM wouldn't make a pimple on a quality VM system's backside.

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Mitel Lurker <wdg

Does anybody actually know of any industry standards for VoIP quality, measurable (and enforceable)?!? I was looking at:

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I could not find any one tool or methodology being clearly advertised as acceptable for verification of proper implementations/deployments, and/or numbers associated with "passing grades"...

Thx again, papi

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Thank you for your reply and suggestions, but I am NOT looking into "identifying" the problems, myself, anymore. We went through all of the above during the initial deployment (we have everything "by the book", from the physical layer, with cat 5e cabling, through to separate ports on the switches, and VLANs for the phones, through to prioritization of traffic, etc.), then went through various TACs (which actually led to replacement of some of the equipment), etc., and the things still do not work quite right.

What I need are some measurable parameters ("quantifiable") as a reflection of VoIP performance ("quality"), and enforceable (or at least acceptable) by industry standards, so that an outside expert could be held responsible for achieving them. Tools for such will be a secondary - obvious - need, of course.

Thx, papi

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since you have a cisco implementation - maybe you should use cisco specific checks.

i would try using the cisco best practice guide for IP Telephony implementations

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there are a bunch of guides for different versions of Call Manager

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Hi papi,

this is a problem IMHO in VoIP. The only real measurements that one can take are MOS tests. There is some effort in the monitoring world to quantify MOS, if measured by machines MOS is suddenly called PESQ.

I would suggest that you define a MOS or PESQ value that should be achived on the network as this is the only important thing for you as an end-user. The rest, things like jitter, delay and packet-loss are important to quality, but should be 'invisible' to you as a user.

Perhaps you can find some ideas on:

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Specifically the 'Measuring VoIP Voice Quality' sections are a good read.

Regards, Arnold.

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Arnold Ligtvoet

Would this perhaps do the trick:

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Reply to
Arnold Ligtvoet

What you've seen in all these replies is that while there are so call industry voice quality standards (not confined to VoIP) they are naturally based on a users perception of what they hear.

You can put in a requirement that the results meet a particular score but that's the same as saying "it's fixed when we think it is" and no reputable company would agree to that (note: REPUTABLE). Add to this that whoever you bring in knows they are working on someone else's screw-up and will want to bill accordingly.

VoIP does work but needs to be properly engineered.

Personally I like a challenge and would work on fixing you problem just for a reasonable hourly rate, as I'm sure many engineers would. But most of us work for, or own, a company and that comes with a different way of doing business. They are not going to want to be locked into a number based on someone's perception of quality, especially if they don't know a lot about you network and how it was put together.

If you want you could go with something like taking 1000 people off the street have them use and rate the system on a scale of 1-10 for quality and require a 90% score. Sounds ridiculous but if you want objective opinions you have to go outside the company.

Good luck, I'm going to monitor this thread and would love to see what you come up with. Feel free to email directly.

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