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To support the various topologies and applications of the Cisco Wholesale Voice Solution, both Cisco and third-party components are required. Some components are required in all topologies. Other components, although optional, are mandatory for certain solutions (such as those requiring SS7 signaling). This chapter lists and discusses the actual components, both Cisco's and those of third parties, that can be used to implement a Cisco Wholesale Voice Solution.
This chapter presents the following major topics:
Table 3-1 summarizes the major components, all of which are Cisco components. Required components are listed first, followed by optional components.
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Note Refer to the most current Cisco Wholesale Voice Solution Release Notes for the latest information regarding IOS versions and the platforms they run on. |
| Component | Description |
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Required. Support small- to large-scale interconnects with wholesaler's TDM-based customers. Platforms include the Cisco 3600 series, Cisco AS5300, Cisco AS5350, and Cisco AS5400, as well as supporting network modules. The Cisco 3600 series is not used in applications requiring SS7 signaling. For more information see Cisco Voice Gateways. |
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Required. Allow network to be scaled to large sizes. Platforms include the Cisco 3660 and Cisco 7200. For more information see Cisco H.323 Gatekeepers and Directory Gatekeepers. |
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Required. Supplement GKs in allowing network to be scaled to large sizes. Platforms include the Cisco 3660 and Cisco 7200. For more information see Cisco H.323 Gatekeepers and Directory Gatekeepers. |
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Optional. However, these components are required in SS7 interconnect solutions. The supported platform is the Cisco SC2200 running Release 7.4 (Cisco SS7 Interconnect for Voice Gateways). For more information see Cisco Signaling Controllers. |
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Optional. However, these components are required in SS7 interconnect solutions. The platform is the Cisco 2611. For more information see Cisco SS7 Signaling Link Termination Systems. |
The above components are discussed in the sections that follow.
The Cisco Wholesale Voice Solution requires a range of small-, medium-, and large-scale PSTN interconnects with the wholesaler's TDM-based customers (typically IXCs, PTTs, or other wholesalers), depending on anticipated call volumes. Platforms include the Cisco 3600 series, the Cisco AS5300, the Cisco AS5350, and the Cisco AS5400, along with various supporting network modules. To offload traffic, similar interconnects may be required. The GWs may handle their own signaling, or they may provide IMTs and receive external SS7 signaling through a Cisco SC2200 running Cisco SS7 Interconnect for Voice Gateways, with Q.931 signaling backhaul.
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Note The Cisco 3600 series is not used in applications requiring SS7 signaling. |
For the modules and signaling types supported by the Cisco VoIP GWs, see Table 3-2.
| 1FG = feature group |
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Note The Cisco Wholesale Voice Solution does not support GW platforms that use MGCP call signaling. In addition, only Cisco SS7 Interconnect for Voice Gateways is used. |
Cisco H.323 GKs and DGKs constitute the gatekeeper core. GKs are mandatory network elements used to scale a wholesale network to large sizes. Directory GKs (DGKs) further supplement network scalability and are mandatory if GK-based carrier interconnect is desired. The Cisco GKs and DGKs supported by the Cisco Wholesale Voice Solution are essentially IOS software images loaded onto a dedicated Cisco 3660 or Cisco 7200 series machine.
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Note The Cisco Wholesale Voice Solution does not support integrated GKs and GWs. |
Cisco GKs perform the following tasks.
Cisco GKs determine the health of H.323 gateways by monitoring registration and unregistration (RRQ/URQ) messages and resource availability indicators (RAIs).
Cisco GKs provide call routing based on destination E.164 addresses. They may use their knowledge of local GW health levels to make routing decisions in order to increase the network availability of the GWs. Cisco GKs may also route calls between remote GKs within the same administrative domain by means of inter-GK LRQ RAS messages. Similarly, Cisco DGKs may also route calls to other carrier administrative domains by means of LRQ RAS messages.
Cisco GKs, in conjunction with an external server (such as RADIUS), may be used for secure call admission in intradomain call scenarios (calls within the same service provider's domain). Cisco GKs also have limited applications in implementing interdomain security functions for calls sent between carriers by means of IP interconnect.
Cisco GKs may act as a control point from which an application server can affect call routing, number translation, call admission/blocking, and the like. These application servers interface with a Cisco GK or DGK by means of GKTMP.
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Note The Cisco Wholesale Voice Solution does not specify any particular GKTMP application, but does not exclude any from being used. |
Cisco GKs have limited abilities to generate CDR reports for calls either in addition to or instead of generating them from the GW. This is an option if the wholesaler either does not own the GWs at a POP, or simply wants to reduce the amount of messaging overhead associated with AAA in its smaller POPs. However, billing in this manner has limitations.
These optional components are used in SS7 interconnect solutions. The supported platform is the Cisco SC2200 running Cisco SS7 Interconnect for Voice Gateways.
These optional components are used in SS7 interconnect solutions. Signaling link termination (SLT) systems are Cisco 2611 platforms that are capable of terminating MTP1 and MTP2 SS7 layers and backhauling MTP3 and higher SS7 layers to the Cisco SC2200 in an SS7 interconnect solution.
This section discusses the additional components that support shared services. Table 3-3 summarizes these components, which are provided by third parties.
| Component | Description |
|---|---|
Required. Ecosystem Partner OSS servers interface with Cisco GW and GK components through AAA RADIUS. For more information about these components, see RADIUS/OSS Servers. |
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Optional. These GKs are used on the edge of the network to complement the Cisco GK/DGK infrastructure and host a variety of applications. Applications will vary among Ecosystem Partners. For more information about these components, see Ecosystem Partner H.323 GKs. |
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Optional. These host enhanced call-routing applications and interface with the Cisco wholesale VoIP network through Cisco GKs or DGKs, by means of the GKTMP interface specification. For more information about these components, see Gatekeeper Application Servers. |
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Optional. These are used in simple carrier interconnect scenarios. The use of OSP for secure settlement transactions requires a clearinghouse entity, or at least a dominant carrier in the interconnect relationship that administers the OSP server. For more information about these components, see OSP Servers. |
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Optional. These maintain a prompt database for GWs running interactive voice response (IVR) functionality for applications such as card services. For more information about these components, see Prompt Servers. |
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Optional. These store a variety files that do not need to reside on the local machine. For more information about these components, see TFTP Servers. |
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Optional. Both Cisco and third-party management systems are supported. These include element management systems (EMSs) and network management systems (NMSs). For more information about these components, see Management Systems. |
| 1The Cisco Wholesale Voice Solution does not require or specify the use of these components, but the architecture does not exclude their use.
2The Cisco Wholesale Voice Solution does not require or specify the use of specific GKTMP applications, but the architecture does not exclude their use. |
The above components are discussed in detail in the sections that follow.
OSS servers interface with Cisco GW and GK components via AAA RADIUS VSAs (vendor-specific attributes), and are required elements of the wholesale network. Current examples include Cisco Secure and billing platforms such as those provided by Cisco Ecosystem Partners MIND/CTI (http://www.mindcti.com) and Belle Systems (http://www.bellesystems.com).
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Note In the Cisco Wholesale Voice Solution, Cisco Secure does not support applications such as debit card, which are dependent on VSAs. For more information about RADIUS VSAs, see RADIUS Vendor-Specific Attributes Voice Implementation Guide at http://www.cisco.com/univercd/cc/td/doc/product/access/acs_serv/vapp_dev/vsaig3.htm. |
VSAs can be used to achieve the following functions, as discussed below:
Cisco GWs send call start/stop records to a RADIUS server by means of AAA. The billing application can extract these records to generate CDRs. CDRs may be shared between carriers as a method of settlement through billing-system mediation applications.
For card services, an AAA RADIUS server may validate end users on the basis of ANI or username and password combinations. The AAA interaction occurs directly on the Cisco GW.
A Cisco GW may run a call script that interacts with an application mounted on the RADIUS server. The server is capable of manipulating call information by means of VSAs in AAA. An example would be a debit card application. The AAA server interacts with a debit-card billing application to determine account balances, call rates, and the time remaining for an individual user. This information is sent to the GW script in AAA VSAs.
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Note In the Cisco Wholesale Voice Solution, Cisco Secure does not support applications such as debit card, which are dependent upon VSAs. |
GKs can administer H.235 security options to perform secure endpoint registrations.
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Note The Cisco Wholesale Voice Solution supports Cisco H.235 security for registration only. For reasons of AAA latency, H.235 security is not supported on a per-call basis. When per-call security is required, Cisco recommends that you use access lists. |
Some billing system vendors support interdomain settlement based on CDRs that are collected from each local domain. This offers a viable alternative to OSP in some cases. Mediation vendors such as XACCT (http://www.xaccct.com) also provide servers dedicated to settling CDRs between different vendors' billing systems. These are known as mediation servers, and are optional components in a wholesaler network.
These GKs may be optionally used on the network fringe to compliment the Cisco GK and DGK infrastructure to host a variety of applications. Individual applications will vary among Ecosystem Partners.
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Note Cisco has identified leading solution providers with which to partner in offering end-to-end benefits.
This forms what is known as the Cisco New World Ecosystem. For more
information about the Ecosystem Partner community, visit
http://www.cisco.com/public/Partner_root.shtml. The Cisco Wholesale Voice Solution neither requires nor specifies where and when these partners should be used on a wholesale network. However, the architecture does not exclude them from being inserted into the wholesaler's network. |
Enhanced call routing applications may optionally reside on an external server. They can interface with a Cisco wholesale VoIP network through Cisco GKs or DGKs that use the GKTMP interface specification.
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Note The Cisco Wholesale Voice Solution does not specify any particular GKTMP applications, but the solution architecture does not exclude adding them into the wholesaler's network. |
To support carrier interconnect, wholesale providers may choose to use OSP servers. (For more information about OSP, see "Open Settlements Protocol (OSP) Clearinghouse Solution.") The use of OSP for secure settlement transactions involves a clearinghouse entity or at least a dominant carrier in the interconnect relationship that administers the OSP server.
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Note TransNexus, Inc. (http://www.transnexus.com) currently provide OSP-based clearinghouse services. |
OSP servers perform the following functions, as discussed below:
By using a secure exchange of certificates, an OSP server can validate whether or not an originating or terminating carrier's GW is a valid participant in the OSP interconnect.
An OSP server generates an access token for each call sent from an originating GW into the OSP-based interconnect. The originating GW includes this token in the SETUP message to the terminating GW. Upon receiving the SETUP, the terminating GW may then send the token back to the OSP server for validation, or may perform the validation locally.
The OSP server provides the originating GW with a terminating GW selected from among registered OSP endpoints.
After a call has ended, OSP usage indicators are sent to the OSP server from both the originating and terminating endpoint. The OSP server uses this information to generate a CDR.
Once CDRs are collected, the OSP server may interface with a billing application to generate settlement billing between the two interconnecting carriers.
A prompt server is an optional component that maintains a prompt database for GWs running IVR functionality for applications such as card services. If they are not too big, prompt databases may be stored locally on the GW in flash memory. Larger prompt databases, such as those needed when there are many branded retailers or when many languages must be supported, may be downloaded dynamically as needed from a TFTP prompt server. TFTP servers are generic third-party devices that can be hosted on a wide variety of platforms.
TFTP servers are used to store a variety of files that do not need to reside on a local machine, and that would otherwise take up available limited memory on that machine. These files can be downloaded as needed. Example files include audio (IVR) files, IOS files, and configuration files (including dial peers).
The Cisco Wholesale Voice Solution supports both element and network management systems.
Element management systems (EMSs) are optional components that are used for managing or provisioning other components in the solution. CVM 2.0.2 provides limited provisioning support and is currently the only EMS supported by the Cisco Wholesale Voice Solution.
Network management systems (NMSs) are optional components that are used for network monitoring, fault management, trap correlation, and reporting. Any NMS can extract this information from wholesale components by means of SNMP. The Cisco Wholesale Voice Solution recognizes CiscoWorks Internet Protocol Manager (IPM) to monitor network QoS, and Cisco Info Center (CIC) to provide fault management and trap correlation. For reporting, it is possible for third-party vendors of reporting applications to provide reports by interfacing with CVM 2.0.2. The Cisco Wholesale Voice Solution recognizes Trinagy (http://www.trinagy.com) as one of these vendors.
Posted: Wed Jan 22 15:17:28 PST 2003
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