Service-Oriented IP Address Management

By BT Diamond IP

The Service-Oriented Enterprise

As organisations strive to increase business flexibility, get to market faster, better serve customers, and more rapidly respond and adapt to change, they are instilling a cultural shift toward a service-oriented mindset. A service-oriented enterprise (SOE) model seeks to achieve these goals across the enterprise. From an IT perspective, deployment of a service-oriented architecture (SOA) provides a structured mapping of SOE objectives to IT applications and infrastructure. The emergence of service-oriented communications (SOC) enables enterprises to further integrate business processes and applications with unified communications technologies such as IP telephony (IPT), unified messaging, email, mobility, conferencing, and presence.

Deployment of SOC and unified communications in particular facilitates the consolidation of communications infrastructures into one environment, enabling employees to communicate more effectively. Such converged services deployments yield significant cost efficiencies through the consolidation of network infrastructure and management using a common network layer. The use of a common network layer also lowers overhead, enables better responsiveness and rapid change, and empowers employees to communicate in the way that suits them best at any moment in time.

The foundation of converged services is the underlying IP network layer over which these services are delivered. Access to these services over a variety of media likewise relies on a solid IP layer, whether access is attained via enterprise networks, MPLS, broadband, or public or private wireless networks. Given this dependence on the common IP layer, it is imperative that the IP network be properly managed, lest the quality of dependent converged services suffers.

IPAM for Converged Services Networks

Effective IP network management requires the combined use of disciplined processes and support tools for configuration, monitoring and troubleshooting. IP address management (IPAM) processes and tools, or preferably a service-oriented IPAM system, should be one of the tools used to ensure service availability and network reliability. Implementing an IPAM system increases network robustness by  tracking and proactively managing IP address space and supporting network services, namely, Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS).

DHCP and DNS network services provide automated IP address assignment and hostname lookup services, respectively, and are critical to providing efficient and easy-to-use converged services. Without accurate DHCP configuration, end users may be unable to obtain IP addresses to access the network. This configuration issue impacts not only computers and PDAs, but IPT phones, wireless laptops, and other IP devices. And without proper DNS configuration, the automated behind-the-scenes name-to-IP address lookup function of DNS can malfunction, adversely impacting network usability. Imagine having to navigate to a website or send an email or an instant message by IP address instead of by name! DNS, when properly configured, performs this lookup for you.

IP address management starts with the creation and tracking of an IP address plan, which must accurately reflect IP address assignments based on geography, device or function. This serves as the “plan of record” upon which further IP address moves, adds, and changes can be applied using appropriate process discipline. The IP address plan also serves as the definitive source of configuration information for supporting network services, DHCP and DNS.

Implementation of an IPAM system can help keep DHCP and DNS services properly configured and functioning. The IPAM system is used to administer the IP address plan and associated DHCP and DNS configurations. A service-oriented IPAM system can streamline and improve overall management performance for multi-service IP networks. A number of IPAM solutions integrate the IP address plan with automated configuration of distributed DHCP and DNS servers. This saves time and reduces errors that might otherwise occur due to multiple entries of information, for example once in a spreadsheet, once in a DHCP configuration tool, and a third time in a DNS text file. A centralised IPAM solution enables the entry of IP information just once, automatically leveraging this information across integrated IP inventory, DHCP and DNS configuration functions.

Service-Oriented IPAM Benefits

While implementing an IPAM solution can yield tremendous benefits even for a monolithic IP network, a service-oriented IPAM solution can amplify cost and time savings for a converged, multi-service network. The following benefits can be achieved when implementing a service-oriented IPAM solution as part of a converged services management strategy:

• Organise address space by service. Implementation of a hierarchical address plan, modeling the routing topology, can help enforce address aggregation policies and per-IP service address allocations. Modern IP networks are structured in a multi-tiered topology reflecting a hierarchy of successive allocations. The hierarchy models the routing topology, commonly deployed using a tiered core-region-access architecture. On top of this, each IP service may require its own addressing hierarchy. For example, VoIP traffic may require a different routing treatment than data traffic does. As a consequence, you may end up with one address space hierarchy comprised of parallel per-service address space hierarchies. A service-oriented IPAM tool facilitates the modeling of this service-oriented address hierarchy.
• Streamline DHCP configuration. Derivation and automation of DHCP server configurations based on the address plan can save time and money, especially with support for IP service-oriented address assignment and device initialisation parameters. Many IP service-specific devices, such as VoIP phones, require DHCP not only to obtain an IP address but for additional initialisation parameters. The ability to configure your DHCP servers to identify such devices by client class and to assign corresponding standard and vendor-specific DHCP option values simplifies service-specific device provisioning, while providing cohesive cross-server configuration and control.
• Automate DNS configuration. As with DHCP, automation of DNS server configurations confers time and cost savings. Modeling and deploying IP service-specific domains, resource record types, and related DNS configuration information using the IPAM system that manages IP address space facilitates information cohesion. For example, when considering deploying VoIP using ENUM, associating a device with an IP address and its associated A/AAAA, PTR and NAPTR records eases the complexity of this otherwise tedious mapping and configuration task.
• Maintain accurate IP inventory. Tracking the IP plan and network services configuration through discovery capabilities is critical to auditing and reconciling assigned addresses against the IP plan. But why bother? Once the plan is in place and DHCP and DNS servers are configured, you’re done, right? If only it was that easy! New users arrive, others move, subnets and domains are added, etc., all on an hourly or more frequent basis. Managing the IP plan requires rigorous updating of the centralised IPAM database not only based on new address assignments but also on network-driven changes like the ad hoc move of a server to a different IP address. Integrated multi-level discovery and reconciliation capabilities within your IPAM system can help you detect unauthorised changes to the network changes and keep the database aligned with the actual network configuration.
• Rigorous management. Beyond configuration and reconciliation, additional network management disciplines apply. Delegating system access to service-based, regional or server-based administrators empowers them to “own” their portion of the network or service and associated configurations. Providing multiple layers of visibility can help align these access permissions with organisational policies and constrain the scope of control, as needed. Meanwhile, global oversight administrator access would likewise be needed for the central IP team to retain overall network visibility and cohesion.
• IPAM-network management integration. Integrating IPAM into broader service-level management tools is important since IPAM, critical as it is, is one component of an overall IP network management architecture. For example, incorporation of service-oriented IPAM into an enterprise-wide ITIL® initiative aligns service-oriented IPAM with the service-oriented IT organisation. An IPAM system can support configuration management and configuration management database (CMDB) functions for IPAM information, as well as support of other key ITIL processes such as change management, incident management, capacity management, release management and others. Web services API capabilities can facilitate this integration.

Summary and Conclusion

As organisations evolve toward a service-oriented enterprise model to increase business flexibility, time to market, customer service, responsiveness and adaptability, they are increasingly deploying service-oriented communications (SOC) technologies. Deployment of SOC and unified communications in particular consolidates diverse communications infrastructures into one environment, enabling employees to communicate more effectively. Such converged services deployments yield significant cost efficiencies through the consolidation of network infrastructure and management using a common IP network layer. The use of a common IP network layer also lowers overhead, enables better responsiveness and rapid change, and empowers employees to communicate in the way that suits them best at any moment in time. It also increases the reliance of the service-oriented enterprise on this common IP network layer.

Effective management of the common IP network layer is critical to successful deployment of SOC and unified communications services. A disciplined and robust IP address plan provides the requisite foundation for SOC. Implementing a service-oriented IP address management (IPAM) solution will automate and centralise IP address planning with full integration of DHCP and DNS services resulting in greater operational efficiencies, enhanced application and service performance, and significant savings. This approach supports robust management of the common IP network layer, while preserving service level process flows and accountability.

IPControl™ from BT Diamond IP is a comprehensive service-oriented IPAM solution. Available as software and or appliances, IPControl supports full IPv4 and IPv6 address inventory, DHCP and DNS configuration capabilities, as well as granular administrator controls, auditing, reporting, integration, inventory assurance and user definability features required for effective IPAM for service-oriented enterprises. Visit us at www.btdiamondip.com for more information.