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PBX Migration – Avoiding the Headaches

June 24, 2009
at 12:00 pm PST

Times certainly have changed. The TDM based PBX is no longer considered the best way to do things and EVERY vendor that makes a phone system is pursuing the IP Telephony market. Trouble is, many of these vendors are struggling in various ways and this is causing unique issues to consider especially when it comes to your time lines. As the old PBX nears ‘End of Usefulness’, or you are expanding your business, or perhaps you are concerned that the service contracts you pay dearly for may not be delivering for you like they did in the past -- you may be ready to make a change. But how? These are big projects and there are many way to approach them. The migration from a TDM based system to an IP based one is the entire focus of our episode tomorrow. We are very excited to welcome our new UC Expert on the team, Tina Shakour, to walk us through it. Tina has a wealth of knowledge and experience for this topic (not to mention the passion) and she is ready to share. Have you registered to watch this? Even if you are reading this note AFTER the air date of June 25, this same link will allow you to watch the replay almost instantly! (what a great time we live in, eh!)Show NotesDid you catch all of Tina’s ‘Must Have List’? imageTina’s list of 5 Must Have ReportsObtain DNIS from your SP Know what you have. Check with your service provider to get a complete list of all incoming lines for any location moving to IP Telephony. Check with the accounting department to make sure the SP doesn’t have different accounts for the same location. Now is the time to check all your analog lines. Are they connected to anything? If they are an old fax or modem line, kill it. Now is not the time to be removing digital lines though! You do not want to cut off a line that is critical to business in some obscure way. Print out the complete list of extensions However you have to do this for your PBX, get a list of every extension in use. Make sure you know what is there and don’t assume that any extension can be deleted. It costs you nothing (other than a little bit of configuration time) to move every extension over to an IP-based system. Be aware of phantom extensions which are used to route calls to other devices or for CTI (Computer Telephony Integration). Double check your protocols How do you connect to the PBX for administration? Can it be accessed remotely through IP? Does it support Q.SIG? PRI? SIP? Older systems may not and in small installations or on keysystems, there may only be analog lines. What will it take to get the system upgraded to support the kind of integration you desire? Not sure what you need? Take a look at the interoperability guides. Know the cost of upgrading protocols if it is needed and the availability of the components. If the system is end of life or end of sale, you may not be able to upgrade. Know the internal routing of calls This goes hand in hand with knowing your incoming numbers and the extensions in your PBX. Be aware of any helpdesk routing, front desk or operators, admins and assistants who cover calls from other persons. Again, this is not an area to cut corners. Knowing how calls are routed inside your company will be important to your success when you make the switchover. Must have reports: all the above and a list of features in use.Chances are very good you cannot produce a magic report out of your PBX of the features being used. For this, you are going to need to go talk to your users. Talk to the operators and the call centers. Talk to the admins and assistants. Talk to the sales guys and the IT department. Be sure you understand what is critical to these groups. You might even share ideas with them on the features the new system will bring that may be of benefit to them. It helps to get your end-users in your corner before the cut-over begins!If you haven’t picked up on this yet, the secret to a successful move from a legacy PBX to an IP system is all in the prep-work. Flipping the switches, putting extensions into Communications Manager -- that is the easy part.The TechWiseTV Workshop -- this is an interactive deep dive with Jimmy Ray Purser on the ‘road to SIP trunking.’ This will be on July 16 so be sure and get registered now -- we almost ran out of Webex Ports on our last workshop.The Cisco Interoperability Portal -- great resource for digging into specific questions you will have for YOUR specific situation.Our Advanced Services Group have taken on this migration topic -- you can see a replay of their webinar and take a gander at the Q&A from that event.The Design Zone has guides for developing a UC Network and Solution that you may find helpful.WarVOX is a suite of tools for exploring, classifying, and auditing telephone systems.http://warvox.org/Blue Boxing -- http://www.blueboxpodcast.com/http://en.wikipedia.org/wiki/Blue_boxSegment 3 -- SIP TrunkingSIP trunks provide connectivity to other SIP devices such as gateways, proxies, voicemail systems, and other Unified CM clusters. Cisco Unified CM 5.x and 6.x introduced major enhancements for SIP trunks and removed the limitations in Cisco Unified CM 4.x, such as single codec support, lack of video support, and the mandatory media termination point (MTP) for RFC 2833 DTMF support. (read more)Release Notes for CUCM Release 7.1(2)SIP Delayed Offer, Early Offer and Early MediaASA and SIP(good configuration examples beyond just SIP as well)SIP inspection NATs the SIP text-based messages, recalculates the content length for the SDP portion of the message, and recalculates the packet length and checksum. It dynamically opens media connections for ports specified in the SDP portion of the SIP message as address/ports on which the endpoint should listen. (read more)Segment 4 -- Hacks, Cracks and WhacksToll Hacking -- ‘2 Staging’Google Hackinginurl:”NetworkConfiguration” ciscoSIP HairpinningJimmy Ray prefers the suite of tools in BackTrack vs. Sivus…(SiVuS is the first publicly available vulnerability scanner for VoIP networks that use the SIP protocol)Learning at Cisco -- Mary Ng Dooley Path:CCNA Voice -- NewLAB: Lab changing for CCIE VoiceTrack -- New video tracks with 2 on TelepresenceLearning at Cisco Self Assessment

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3 Comments.


  1. i did a migration from a alcatel 4200 with no pri or anithing to a callmanager 6.1.2 B.E. it took 6 months. it went well expect one thing a global phonebook i dont know if you know this but callmanager dosent have a phonebook example: my boss calls from his cell and the number apears not BOSS”” in the alcatel it was relative simple task to do this. i have the UCCX 5.0 enhanced and 80 Cisco IP Phones.”

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  2. Tina Shakour

    Hi Marcos – It sounds like you don’t want CallerID, but to have specified numbers resolve to an internal directory or phonebook? So if your boss is Mr. Withers and that is what his cell phone passes on CallerID, you want it to resolve to something you have set where it comes up on your phone as Boss”” and not Mr. Withers. If I have it call correctly, I don’t believe this is supported but you may want to double-check the interop guides again here: http://www.cisco.com/en/US/netsol/ns728/networking_solutions_program_category_home.htmlIf you are doing within Contact Center, then this should just be a database dip to pull the record and bring up the correct name. Check with the VAR who installed your system and see if they can script it in for you.”

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  3. So do you suggest it’s better to migrate to IP based systems instead of sticking with PBX? What are the exact advantages of using a small business phone with IP Telephony? You are right it’s a relatively new concept, I still don’t know enough about it in order to make a decision.”

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