IPv6 has snuck up on us. In fact, as of October 1, 2003, all new equipment has been IPv6 compatible thanks to an edict from the US Department of Defense. So here we are… IPv4 is no longer the cool kid on the block.
How will this affect the Cisco UC environment and future deployments?
Join me as I take a look at IPv6 and how it will affect our job as voice engineers. This is part one of a multi-part mini-series designed to provide bite size information on this change that is upon us.
Cisco’s stance – No IPv6 only in UC
Cisco recommends that IPv6 is deployed in a dual-stack CUCM cluster with approved dual-stack devices. The purposed of this best-practice is to avoid an IPv6-only deployment. So for now, all you avid IPv6 fans are still stuck with a mixed-mode environment at this time. Expect this to change over the next few years as IPv6 becomes more familiar as IPv4 is slowly deprecated.
Benefits of IPv6 over IPv4
- Larger address space: 128 bit addressing v. 32 bit addressing
- Address scopes: Defines the region (span) where an address can be identified as a unique identifier of an interface. These spans are the link, the site network, and the global network, corresponding to link-local, site-local, and global addresses.
- Stateless Address Auto-Configuration (SLAAC): IPv6 hosts can be configured automatically when connected to a routed IPv6 network using ICMPv6 router discovery messages. Hosts can also used DHCPv6 if SLAAC is not suitable.
- Multicast: Unlike IPv4, multicast is natively built into IPv6. Multicasting can be achieved by using the all-hosts group address (FF02::1).
- Streamlined header format and flow identification: The IPv6 header format reduces router processing overhead by using a fixed header length, performing fragmentation on hosts instead of routers, and using an improved header extension method and a new flow label to identify traffic flows requiring special treatment.
- Mobile IPv6: This exciting feature, though not supported by Cisco IP phones or other UC equipment (at this time), allows a mobile node to change its locations and addresses, which still maintaining a connection to a specific address that is always assigned to the mobile node. Basically, a roaming IP addressing model that allows the device to always be connected.
- Network-later security: IPSec in IPv6 is an integral part of the protocol suite. Because of its reduced payload and performance overhead, IPv6 UC products use TLS and SRTP for authentication and encryption. Be prepared to start using secure-everything in future deployments: media/signaling streams, conferencing, transcoding, etc. The fact that PVDM3s support more sessions than the older PVDM2 makes this change more feasible.