Spotlight

New open standard quickly fulfilling the promises of network convergence

Hopefully you caught last month's article on LLDP (Link Layer Discovery Protocol), the industry standard alternative to Cisco's proprietary CDP and CDPv2. As my last installment noted, LLDP provides exceptional base capabilities for integrating network services, but on its own is not sufficient to enable the features and functionality demanded by IP telephony and video applications.

This month I will be highlighting the specific requirements for truly converged networks and how the implementation of LLDP-MED (Link Layer Discovery Protocol – Media Endpoint Discovery) gives organizations a threefold advantage, with technology, ease of use and business benefits.

Early in 2004, the LLDP-MED workgroup was initiated by ProCurve Labs with the intent to enhance the existing LLDP standard. We wanted to address the unique needs that video and voice demand in a converged network. LLDP-MED is an enhancement to IEEE's 802.1AB LLDP, adding media- and IP telephony-specific messages that can be exchanged between the network and endpoint devices.

Before I outline the specific advantages of LLDP-MED, how it differs from other convergence standards deserves some attention. There are essentially two paths that lead toward a converged network: one open and industry supported, and the other proprietary. Here's a quick look at how LLDP and LLDP-MED differ from Cisco's CDP and CDPv2:

• LLDP is an open standard, multi-vendor solution
  • No proprietary "lock-in"
  • More choices for best-in-breed IP telephony and video solutions
• LLDP is seeing widespread adoption, including ProCurve, Avaya, Nortel, Mitel, Extreme, Adtran and more
  • CDPv2 is proprietary, and as such, is supported only on Cisco infrastructure
• LLDP runs after 802.1X, whereas CDP runs before authentication
• LLDP-MED provides auto-deployment of layer 2 and layer 3 QoS policies
  • CDP configures only the voice VLAN (IP precedence and COS are hard coded)
• The LLDP-MED standard provides support for auto-deployment of streaming multicast and/or video conferencing
  • It supports multiple convergence policies on a given port for plug-and-play deployment with compatible devices (e.g., plug-and-play video surveillance cameras)
• LLDP-MED provides detailed IP phone inventory management
  • The Ethernet switch collects model, manufacturing, software, firmware and asset information, since few IP phones and video devices support SNMP
• LLDP was designed for easy extensibility
  • Organizationally specific (e.g., LLDP-MED within TIA) and private vendor extensions can be added without concerns of new identifier conflicts to ensure future interoperability
• LLDP-MED provides multiple format location information concurrently
• LLDP-MED advertises endpoint power priority and backup power conservation
  • This enables future capability for phones and other devices to conserve power and disable non-critical functions to extend battery backup power life during emergency situations

From a technical standpoint, LLDP-MED provides exceptional interoperability, IP telephony troubleshooting, automatic deployment of policies, inventory management, advanced PoE and location/emergency call service capabilities. These sophisticated features render converged network services easier to install, manage and upgrade, and I will spend more time going into these capabilities in greater detail in a subsequent newsletter article. Stay tuned!

In addition to its notable technological benefits and ease of use features, LLDP-MED helps significantly reduce operational costs:

• Plug-and-play provisioning speeds initial deployments and reduces configuration errors with QoS and VLAN assignments
• Accurate physical topology and device inventory simplifies management and maintenance
• Subsequent moves, adds and changes take minutes instead of hours or days
• Consolidated management tools ease network administration
• Automated diagnostic and consistency checking reduces operator and configuration errors and helps maintain uptime

There are two paths to consider. Which one will you take?

Barbra Stuter is a Solutions Marketing Manager at ProCurve Networking by HP. She is responsible for defining and driving ProCurve's mobility and convergence solutions portfolio.