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Comparison between Cisco Ip Telehpony and Avaya Definity solution

Does anyone have a comparison document between Cisco IP telephony solution and Avaya Dfinity G3 IP-PBX system ?



Mohamed Abdallah

New Member

Re: Comparison between Cisco Ip Telehpony and Avaya Definity sol

Here are some points that I was told.....

1. Unlike the Cisco CM solution which is a true end-to-end IP telephony solution, the Avaya Definity IP Tel solution is more a hybrid solution. Performance is constrained by its TDM architecture.

2. The data infrastructure at a vast majority of customer sites is made up of Cisco equipment. The Cisco IP telephony solution can leverage this existing infrastructure (eg. Cisco phones can obtain Aux. VLAN information and detect Inline power). This is because the network is truly converged. In comparison, Avaya IP phones cannot leverage the benefits of the infrastructure (In fact, the phones cannot even obtain aux.vlan information from Avaya switches. They need to rely on DHCP custom option 176).

3. If the customer wants to IP enable his Definity PBX and is running an old software version or an incompatible backplane, he/she may need a new cabinet and a new set of circuit packs. Imagine if there are several such PBXs at the customer site. The cost of upgrading them would exceed the cost of installing a Cisco IP tel solution.

New Member

Re: Comparison between Cisco Ip Telehpony and Avaya Definity sol

1. Avaya Communication Manager is a hybrid solution because of the company heritage (providing telephony services 2 decades prior to Cisco becoming a company). The Avaya VOIP solution is not limited by the TDM bus in an all VoIP solution. This because Avaya supports shuffling & hairpinning. Shuffling occurs between two IP Phones to form an audio stream. This stream occurs between the phones using the Avaya gateway. Calls only hit the TDM bus when utilization of any of the 600+ call features are required during conversation, i.e. hold.

2. Costs of upgrading to IP telephony capability are nomimal for a customer who has remained some what current in software releases. I have not seen a cabinet replaced yet due to add IP funtionality. Greater than 90% of circuit packs remain in many systems that are upgraded. Only the C-LAN & Med Pro cards are added when supporting Avaya IP Phones. While an upgrade could cost be close in price to a forklift Cisco solution, it is the cost savings of leveraging the equipment that has already been purchased that customers like.

New Member

Re: Comparison between Cisco Ip Telehpony and Avaya Definity sol

Don’t forget to factor in support. Consider what you are paying for Avaya support vs what the support contracts will be with the Cisco equipment. I have had some amazing support from Cisco, software upgrade are usually FREE with a maintenance contract and very cheap without (CCM 3.2 to 3.3 =$100). Also at any time you can call Cisco and ask them how to configure the system, they will walk you through all of it.

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