Changes
→Network Topology: Correct details about upstream bandwidth and IPv6
=== Network Topology ===
In Blacksburg, CNS has redundant fiber uplinks from the [[Andrews Information Systems Building]] to an upstream router in Equinix's [[Ashburn, Virginia]] datacenter. At Equinix, CNS has about 4 Gbps aggregate bandwidth of for commodity Internet from its Cogent uplink in , as well as, through the [[Andrews Information Systems BuildingMid Atlantic Terascale Partnership]], which is fed to campus via redundant fiber connections to both Burruss Hall and Cassell Colliseum. Owens Hall, Hillcrest Hall, and Shanks Hall also serve as routers for some buildings. Additional connections for [[Network Virginia]], [[National LambaRail]], [[Mid-Atlantic Terascale PartnershipLambdaRail]], and [[Internet2]] exist at AISB. Nearly all ethernet portals on campus are capable of 100 Mbps or Gigabit speeds, due to fiber interconnects between buildings; however, intrabuilding wiring varies in age and may not support high speeds. The vast majority of campus IPv4s come from two directly-allocated blocks (128.173.0.0/16 and 198.82.0.0/16).
From the Andrews Information Systems Building, there are redundant fiber connections to the main campus at both [[Burruss Hall]] and [[Cassell Colliseum]]. [[Owens Hall]], [[Hillcrest Hall]], and [[Shanks Hall]] have intermediate routers for some buildings. Nearly all ethernet portals on campus are capable of 100 Mbps or Gigabit speeds, due to fiber interconnects between buildings; however, intrabuilding wiring varies in age and may not support high speeds. The vast majority of campus IPv4s come from two directly-allocated blocks (128.173.0.0/16 and 198.82.0.0/16). CNS is a leader in the transition to IPv6, as their [[w:Autonomous System|ASN]] consistently ranks in the top 5 in terms of percentage of IPv6 traffic, according to [http://www.worldipv6launch.org/measurements/ World IPv6 Launch Measurements]. A dual-stack topology exists for the entirety of campus, with but not all systems connected to the notable exception of network are IPv6-enabled. One system that notably lacks connectivity is the main university vt.edu website, which is due to a lack of support from the load balancers currently in use. HoweverFor legacy reasons, Virginia Tech does not currently continues to use its assigned IPv6 block (2607:b400::/32); the addresses used are from a /48 sub-allocated allocation from the [[w:University of Maryland|UMDUniversity of Maryland]], instead of its assigned IPv6 block (2607:b400::/32). It is unknown when the new address space will begin to be used.
In December 2011, CNS announced that a contract had been awarded to IBM and Avaya for ''Unified Communications'', a project to both replace the aging ROLM phone system with SIP phones and upgrade the network infrastructure in each building. This has also somewhat reduced monthly rates of common telephone and ethernet services for departments. While most buildings will be undergoing upgrades through 2014, it is unknown whether or not each will have full gigabit speeds at actual user ports. It is also unknown whether users will be able to use SIP softphones in conjunction with this.