IP Telephony Comparative Analysis
Cisco IP Telephony v.s. Avaya IP Telephony v.s. Open Source IP Telephony
What I will during the next series of postings is to:
- Describe the overall architecture of the Cisco IP Telephony solution.
- Describe the overall architecture of the Avaya IP Telephony solution.
- Describe the specific technical solution details for an exemplary 1500 phone extension/user deployment, both utilizing Cisco’s and Avaya’s solutions
- Determine their approximate price list cost
- Finally, compare both of them to a solution based on Open Source IP Telephony (Asterisk).
So on this one, I will cover Cisco’s IP Telephony.
STEP 1 – Cisco IP Telephony
Cisco is a recognized leader in IP communications and has recently developed the “Unified Communications” concept. As per Cisco’s website: “Using a systems approach, Cisco combines the strengths of intelligent networking with security, open application programming interfaces (APIs), and self-service business applications”.
According to Cisco:
“IP Telephony encompasses the full suite of telephony services enabled by VoIP, including the interconnection of phones for actual communications; related services such as billing and dialing plans; and basic features such as conferencing, transfer, forward, hold, and many more. These services might previously have been provided by a private branch exchange (PBX)”.
“IP communications evolves the IP Telephony concept to include business applications that enhance communications to enable applications such as unified messaging, integrated contact centers, and rich-media conferencing that combines voice, data, and video”.
Cisco’s Unified Communications concept “takes IP communications a step further with technologies such as Session Initiation Protocol (SIP) and presence and mobility solutions. These technologies unify and simply all forms of communication-independent of location, time, or device, where users can be reached at any time based on their preferences and can communicate through any media using any device”.
Here I will explore in further detail, Cisco’s IP Telephony solution architecture.
Cisco’s IP Telephony solution is very flexible, in order to easily accommodate for a wide range of requirements, especially size.
The main components of this solution are:
- Cisco Unified CallManager-Call-processing software that manages voice and video calls between IP phones, media processing devices, VoIP gateways to the public switched telephone network (PSTN), and multimedia applications
- Cisco Unified CallManager Express-Software embedded in Cisco integrated services routers to provide call processing for small businesses and branch offices.
- Cisco IP Communicator-Software that delivers advanced telephony functions to Microsoft Windows-based personal computers for Cisco Unified CallManager and Cisco Unified CallManager Express users
- Cisco Unified IP phones-Includes hard, soft, and video phones for all types of businesses and users from the executive office to the factory floor
Therefore, a number of different deployment configurations can be developed in order to best fit any given site requirements. It should be noted that the only limitation is the Call Manager capacity.
Usually the most efficient configuration is the one which considers a centralized data centre model. However, intermediary smaller and more dispersed topologies can also be implemented as follows:
- Large Site General Office ~ 500 users or more
- Medium Site Manufacturing Plant ~ 40 to 500 users
- Small Site Sales Office ~ less than 40 users
LARGE SITE (General Office) – A large site by definition is a site with greater than 500 users. At a high level the site would have its own Call Manager cluster to provide voice services to the site. All hardware for services, e.g. voicemail, voice gateway, conferencing and other application hardware would also be located at the site. The cluster can also serve as a centralized call manager for smaller sites.
MEDIUM SITE (Manufacturing Plant) –Here a small cluster would suffice for the Medium Sites (Manufacturing Plants) which would be hosted in the Large Site (General Office) Call Manager. Medium Sites would connect to centralized Call Manager through the Data Network (ideally a Private Data Network). At the sites there will be individual telephone handsets and the Voice Gateway or Voice Router(with SRST) providing connectivity to Private VoIP/Data Network and the Public Telephone Network.
SMALL SITE (Sales Office) – These is a configuration conceived for those small Sales Offices that usually do not have unlimited WAN bandwidth. Cisco Unified CallManager Express-Software is a feature that can be used for small sites (less than 40 users). Cisco Unified CallManager Express (ITS) software would reside on the Site Router and provides basic telephony and telephony features. With ITS calls would be made out via PSTN link. The Voice Switch (IP PBX) software will actually be hosted within the Site Router (not a Call Manager).
Based on the above shared site configuration examples, Cisco claims that: “Unlike telephony solutions from other vendors, Cisco Unified Communications securely integrates all information types-including voice, data, and video-using intelligent technologies that are built into, rather than onto, the network”.
I will leave here on the description of Cisco’s overall IP Telephony solution. In case you may want to get further details please feel free to contact us, request further details by sending to comment to this posting. Next time I will cover Avaya’s IP Telephony solution.