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HP's E-Series ZL Ethernet Modules Sip Power: Page 2 of 2

802.3az operates independently of PoE and PoE+ interfaces. There is no power budget to manage and no schedule to define, unlike with PoE, 802.3af, PoE+ and 802.3at. Ports that are using PoE and PoE+ continue to provide power regardless of the ports' LPI mode.

HP's new ASIC modules also conserve power using features such as Smart Clock Gating, which allows the switch to turn off unused processing modules to conserve power. For example, if the switch doesn't have any access control lists, the ACL processing can be powered down until needed.

Whether 802.3az will have an impact on power costs remains to be seen. Given the amount of broadcast traffic on the network due to everything from Spanning Tree data units to Windows file sharing, there is hardly ever a time when a NIC isn't preparing to send some data. In some rare cases where network devices don't use any broadcast services, like network cameras or VoIP phones, there might be some savings if network broadcast traffic is curtailed.

The new ZL modules can be used in both new and existing 8200s and 5400s and are hot-swappable. The switch must be running the HP K15 operating system to enable 802.3az. In terms of licensing, HP is removing the premium license. Advanced Layer 3 features such as PIM, OSPF and EIGRP are now part of the base price. Now, all features are available for the same price. The 5400 base price increased only $100, to $4,299, and the 8200 price dropped slightly.