Thursday, 8 November 2012

Migration to VoIP


How a Company would move their network to VoIP

There are many different strategies to go about this. Some companies, if they are a new, come in and just say that we are brand new company and we don’t want to waste money on PBX system (figure below) 

 
Why don’t we just get a VoIP system (figure below).


But for most companies, they will be running PBX system for years and for them to move their entire system on VoIP is a shock. As they had invested 100s of 1000s of dollars on PBX systems (depending on the size of the business) why would they throw that all away to get free long distance? And when they will put on cost on a spreadsheet, they will know that the cost savings would not be realized for decades. So these types of companies might use a “two phased approach”.

Phase 1:

Phase 1 to move over VoIP system is ‘to keep all your PBX system’, so you keep your PBX, your phones. Just re-equipped your routers or buy new routers that allows you to connect the PBX system through WAN and PSTN.
 


It is very low cost to get some new routers or new Modules like VWIC (voice and WAN interface card) that allows the router to connect with PBX system through a T-1 line and also connect the router to the PSTN via a T-1 line. Now we not only can connect our router with IP WAN, but we can also connect our router with the voice world (PBX, PSTN). 

It gives us the capability to choose one of two paths any time you communicate to the offices. If your WAN link is up and has bandwidth, your calls between the offices will go through WAN and if WAN is down then we can use PSTN as a backup. 

It gives us many of the benefits of VoIP like free long distance between the offices, compressing the voice across WAN, we get rid of Tie Lines between the offices with has high reoccurring monthly cost. So we get a lot of cost saving by just buying some new routers or modules to connect our PBX through WAN rather than just PSTN. This is phase 1 migration/upgrade. There are companies that have this phase 1 type set up and they want to upgrade to phase 2 which is difficult to maintain as compared to phase 1 in which we have a back up of PSTN.



Phase 2:

In phase 2 we get rid of PBX system, it is the new voice system which has Call Manager Express which is now known as Cisco Unified Communication Manager Express as a standalone device OR we have a Communication Manager Express running on Router (this is what we are going to deal with in CCNA voice) and we will use new phones here that connect with switches and your everything is end-to-end VoIP

It is also possible to have a hybrid, we can have half of the network like phase 1 and half like phase 2. For example Intel, which is a big company and has a lot of offices and all of their new Fabrication Plants will have phase 2 styled end-to-ends VoIP and all of their existing fabrication plants still has PBX systems and they want to keep them in that way until the maintenance expires on the PBX systems then they will move them out. So it is totally possible to have phase 2 connected through routers to phase 1 and convert back and forth between those calls. 



When we move over VoIP we should make sure that we take away the fear, it is not something that next year everything would be VoIP, The Internet Blah Blah Blah ……. Don’t worry about it as PBX system will be around for years, very scary statistics that 2 million people in America still use rotary phones. People still use them as they just works fine. So VoIP is not going to be one of those things that will take the world by storm and everybody running it, it going to take the back end. As we know rotary phones still exits and users send their audio to SP via these rotary phones and the SP can be converted to VoIP. 

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