Direct Inward Dial for Pots Peers

Configuration Tasks

prefix, “9,” to the front of the remaining numbers, so that the actual numbers dialed is “9, 2222.” The comma in this example means that the router will pause for one second between dialing the “9” and the “2” to allow for a secondary dial tone.

Direct inward dial (DID) is used to determine how the called number is treated for incoming POTS call legs. As shown in Figure 5, incoming means from the perspective of the router. In this case, it is the call leg coming into the access server to be forwarded through to the appropriate destination pattern.

Figure 5 Incoming and Outgoing POTS Call Legs

PBX	Cisco AS5800	Cisco AS5800	PBX
		IP
		cloud

	Incoming	Outgoing
	call leg
		call leg

22356

Unless otherwise configured, when a call arrives on the access server, the server presents a dial tone to the caller and collects digits until it can identify the destination dial peer. After the dial peer is identified, the call is forwarded through the next call leg to the destination.

There are cases where it might be necessary for the server to use the called-number (DNIS) to find a dial peer for the outgoing call leg—for example, if the switch connecting the call to the server has already collected the digits. DID enables the server to match the called-number with a dial peer and then directly place the outbound call. With DID, the server does not present a dial tone to the caller and does not collect digits; it forwards the call directly to the configured destination.

To use DID and incoming called-number, a dial peer must be associated with the incoming call leg. Before doing this, it helps if you understand the logic behind the algorithm used to associate the incoming call leg with the dial peer.

The algorithm used to associate incoming call legs with dial peers uses three inputs (which are derived from signaling and interface information associated with the call) and four defined dial peer elements. The three signaling inputs are:

•Called-number (DNIS)—Set of numbers representing the destination, which is derived from the ISDN setup message or CAS DNIS.

•Calling-number (ANI)—Set of numbers representing the origin, which is derived from the ISDN setup message or CAS DNIS.

•Voice port—The voice port carrying the call.

The four defined dial peer elements are:

•Destination pattern—A pattern representing the phone numbers to which the peer can connect.

•Answer address—A pattern representing the phone numbers from which the peer can connect.

•Incoming called-number—A pattern representing the phone numbers that associate an incoming call leg to a peer based on the called-number or DNIS.

•Port—The port through which calls to this peer are placed.

14Cisco IOS Release 12.0(7)T

AS5800 specifications

Cisco Systems has long been a leader in the networking and telecommunications field, and its AS5800 series of routers exemplify this tradition. The AS5800, along with the AS5850, AS5350, AS5400, and AS5300, provides robust solutions for service providers and enterprise-level networking applications. Each of these models has distinct features and characteristics that cater to the evolving demands of internet traffic and data processing.

The Cisco AS5800 is designed for high-capacity routing and optimized for broadband services. It supports a wide range of services, including voice, data, and video applications, making it a versatile option for service providers looking to deliver integrated solutions. It is equipped with advanced quality of service (QoS) features that ensure bandwidth is allocated effectively, holding strong even under heavy traffic conditions.

In comparison, the AS5850 offers superior processing capabilities and is typically utilized in larger-scale implementations. This model supports high-density interfaces, allowing numerous connections without compromising performance. Its architecture includes enhanced MPLS (Multiprotocol Label Switching) support, enabling more efficient traffic management and better utilization of network resources.

The AS5350 is known for its scalability and energy efficiency, ideal for voice-over-IP (VoIP) and media gateway applications. It supports various telephony features, such as protocol interworking and transcoding, making it a preferred choice for organizations focusing on digital voice technologies. The AS5300, while slightly older, continues to be a valuable asset for less demanding networks, offering reliable performance with VoIP capabilities and basic data applications.

The AS5400 bridges the gap between high-performance routing and operational efficiency. It incorporates Cisco's proprietary technologies to ensure seamless connectivity and robust failover systems. This model is highly regarded for its security features, protecting network integrity and providing peace of mind for businesses relying on sensitive data transfer.

Overall, Cisco’s AS5800 series showcases a progressive evolution of routing capabilities with enhanced features tailored for resilience, scalability, and performance. These routers not only address the technical needs of modern networks but also strategically position organizations for future growth in an increasingly digital world. Each model, with its unique attributes, continues to support the varied demands of global communication infrastructures.