Assist Telco and ISP engineers and technicians in their transition to IP telephony
* Assists traditional telco engineers and technicians in designing, implementing, and supporting VoIP networks
* Provides a step-by-step approach to designing a VoIP network
* Outlines each VoIP technology components with detailed descriptions of possible applications
* Provides a thorough description of Voice over IP for those new to the technology
Voice over IP (VoIP) is a fast-growing technology within telcos and ISPs. VoIP is significantly reducing the cost of transmitting telephone calls and enabling small companies to enter the +$50 billion marketplace. Many telcos and ISPs are entering this market while VoIP is still in its infancy. As a result, there is an urgent need for telco and ISP engineers to learn this new technology. This book will assist telco engineers to transition to IP networking with a focus on VoIP networks. This book introduces the fundamentals of IP networking as it applies to transmitting voice calls using IP packets. Key telco-based technologies such as SS7 are reviewed. A unique approach is that the book outlines each component of VoIP technology while describing the application of the technology. This is accomplished by describing key steps in designing an operational VoIP network, thereby enabling the reader to understand how this technology is applied.
Chapter 2, “VoIP Network Architectures: H.323, SIP, and MGCP,” describes a managed voice and data service architecture that uses a call agent. A call agent solution is commonly used for the small and medium-sized business (SMB) market. This solution uses an integrated access device (IAD) at the customer premises that supports voice and data using IP or Asynchronous Transfer Mode adaptation layer 2 (AAL2) transport over a T1 access link to the service provider.
This chapter continues the focus on offering managed services to SMBs. Service providers that traditionally use time-division multiplexing (TDM) access and that need to add other service offerings can bundle voice and data services over a single access link to the customer. For example, traditional T1 circuits that are offered to customers to interconnect their private branch exchange (PBX) to interexchange carriers (IXCs) can now be used instead for integrated voice and data traffic, thereby eliminating the need for multiple access links between the customer and the service provider.
Three areas are discussed to help provide an overview of bundled voice and data service architectures:
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Overview of Managed Voice and Data Services
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Managed Voice and Data Services Using AAL2
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Fundamentals of AAL2
Overview of Managed Voice and Data Services
Integrated voice and data is a new service that is offered by service providers. The architecture design to deploy managed voice and data services is based on many factors. One of these factors is the required customer premises equipment (CPE), which is based on the type of business customer.
Two general types of business customers exist. One is a business customer with fewer than 100 users, such as a doctor’s office, an insurance agent’s office, or a small home office. These businesses are normally single-site locations that require telephony services, Internet access, firewall, and Virtual Private Network (VPN) services. Typically, these businesses do not have older networking protocols, such as AppleTalk or IPX, and they do not have a full-time support staff to maintain their own private network. A service provider can support these services with an IAD on the customer premises, such as a Cisco 2400.
Using PassGuide online virtual CCVP practice engine, easy to know well CCVP Training knowledge and pass the Cisco CCVP certification exams.The second type of business customer is an enterprise customer. An enterprise customer has a large installed base of devices that supports many flavors of protocols, sophisticated routing designs, multiple T1s, and back-hauling needs. An enterprise customer needs a multiservice platform, such as the Cisco 2600 and 3600. Many of these enterprise businesses have their own large private networks and their own full-time staff to maintain their multiservice network. However, because of various reasons, such as fast growth and economics, many of these large customers are outsourcing some or all of their services to service providers.
Integrated Access Architectures
Traditionally, service providers offer TDM services that connect a customer’s PBX to an IXC Class 4 switch, which provides long distance voice services. Many of these service providers are currently switching from using a TDM-based infrastructure to using a packet-based infrastructure, either IP or ATM. This approach allows for a more efficient method to provide voice transport and also helps to integrate voice and data services over one access link to the customer premises.
NOTE
Many incumbent carriers are adding IP to their core ATM network by inserting Multiprotocol Label Switching (MPLS) technology. This change enables service providers to shift from transport service offerings to IP-based service offerings.
ADSL and T1 ATM are two types of access technologies that can be supported between the SMB and the service provider.
Other Cisco IADs
Other IADs available for SMBs are the Cisco 827-4V and the 1750. Both of these IADs support four Foreign Exchange Station (FXS) interfaces, and the 1750 also supports FX0 and E&M interfaces. The 827-4V supports a fixed configuration that includes Ethernet and DSL WAN-access only, and the 1750 supports a modular configuration that includes Fast Ethernet and multiple WAN options, such as DSL and T1 access. To help further differentiate these two IADs, the 1750 supports dual WAN interfaces for WAN backup or load sharing, hardware Triple Data Encryption Standard (3DES) encryption, and Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP) routing—these capabilities are not present in the 827-4V. The 827-4V is well suited for small offices that do not require the extra capabilities of the 1750 and are not concerned with expandability, but do require core services such as basic voice (FXS), VPN, and a firewall from their service provider.
More info:Voice-Enabling the Data Network: H.323, MGCP, SIP, QoS, SLAs, and Security (Networking Technology)
[...] Recommended Reading Cisco IP Communications Express: CallManager Express with Cisco Unity Express Cisco IP Telephony: Planning, Design, Implementation, Operation, and Optimization Cisco Voice over Frame Relay, ATM and IP Configuring CallManager and Unity: A Step-by-Step Guide Deploying Cisco Voice over IP Solutions Troubleshooting Cisco IP Telephony Voice over IP Fundamentals, Second Ed. Voice-Enabling the Data Network: H.323, MGCP, SIP, QoS, SLAs, and Security [...]