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  • WRITTEN BY DAVID BOMBAL   Learn how to save hours of time configuring Cisco routers and switches with this FREE E-Book You too can use the CLI like an expert by learning the commands in this FREE EBook (Worth £49.99) This EBook has 12 chapters covering topics such as: – “do” – “/” – “|” [...]

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  • WRITTEN BY DAVID BOMBAL I have often seen that Digital Signal Processors (DSPs) cause a lot of confusion. Hopefully, the next series of articles will give you the insight to know what they are used for and how to spec them in a router. You will also learn how to configure the DSPs for various [...]

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  • WRITTEN BY DAVID BOMBAL Here are questions to test your knowledge of CCNA Voice IIUC topics. These are updated on a regular basis, so keep checking to see more. What are the three VTP modes on Cisco switches? A) Master B) Client C) Backup D) Server E) Transparent F) Primary Answer: B, D, E – [...]

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  • Written by Administrator Using GNS3 and Call Manager Express and others Here are more great links! How to build a voice lab with GNS3 and VMWare How to use a third party SIP phone with Cisco routers using GNS3 How to setup Call Manager Express (CME) router using GNS3 How to configure Cisco Unified Call [...]

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  • WRITTEN BY DAVID BOMBAL In a previous articile, we discussed the DSP Calculator and how to use it for sizing. We also discussed sizing DSPs for Voice Termination (See here for details) Here we will continue the discussion talking about transcoding. Transcoding overview: Transcoding is the process of converting an input stream from one codec [...]

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  • WRITTEN BY DAVID BOMBAL Call Manager Express (CME) is a router based VoIP solution currently supporting up to 240 phones. It provides many of the features of Call Manager for a small business. In this example, I am going to configure 5 phones on my CME system. CME is based on router IOS. So no [...]

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  • WRITTEN BY DAVID BOMBAL Here we start with configs that have been available on Cisco routers for a long time, but are as useful today as ever. We start with four analog phones connected to two routers. 1000 & 1001 are connected to R1 and 2000 & 2001 are connected to R2. FXS ports – [...]

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  • WRITTEN BY DAVID BOMBAL When a Cisco IP phone boots up, it requires an IP address to function. The IP address can be manually configured on the phone, but that is a lot of work if you have 240 Cisco IP Phones! Rather than manual configuration, it is a lot easier to set up a [...]

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  • WRITTEN BY DAVID BOMBAL How many phones and directory numbers can be configured on Cisco Unified Communications Manager Express by default? Answer: Zero! Yes, by default, no EPhones or directory numbers can register. Before doing anything else, the following configuration is required: Router>enable Router#configure terminal Router(config)#telephony-service Router(config-telephony)#max-ephones 4 Router(config-telephony)#max-dn 8 This allow up to 4 [...]

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  • WRITTEN BY DAVID BOMBAL It is important as a CCNA Voice candidate to understand the various codecs that are supported by Cisco IP phones and the bandwidth that they each use. Various codecs are supported on Cisco IP Phones including: G711 G729 G729a iLBC G711 G711 provides toll quality voice – in other words, the [...]

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