Abilene

Abilene[] is another project of UCAID. It's complementary to Internet2 in the sense that the main goal of Abilene is to provide a primary backbone network for the Internet2 project. UCAID, in partnership with Qwest Communications, Nortel Networks, and Cisco Systems, has developed the Abilene network. Abilene provides the high-performance interconnect services among the Internet2 regional aggregation points. The primarily OC48c (2.5 Gbps) POS (Packet Over SONET) Abilene netw..

Steady-State Operation by Continuing to Send Joins

To maintain the forwarding state of interfaces, PIM-SM routers must send PIM Join messages periodically. If a router fails to send Joins periodically, PIM-SM moves interfaces back to a pruned state. PIM-SM routers choose to maintain the forwarding state on links based on two general criteria: ■ A downstream router continues to send PIM joins for the group. ■ A locally connected host still responds to IGMP Query messages with IGMP Report messages for the group. Figure 20..

Core QoS Considerations

Several options exist to meet strict SLA considerations for loss, delay, and jitter in the service-provider MPLS VPN core: •    Aggregate bandwidth overprovisioning •    DiffServ in the backbone •    MPLS traffic engineering (which might or might not be used in conjunction with DiffServ in the backbone) Aggregate Bandwidth Overprovisioning Aggregate bandwidth overprovisioning is a common trend in the service-provider backb..

IEEE 802.11 DCF

Interframe Spaces, shown in Figure 11-3, allow 802.11 to control which traffic gets first access to the channel when carrier sense declares the channel to be free. Figure 11-3. IEEE 802.11 DCF Interframe Spaces [View full size image]     802.11 currently defines three interframe spaces: •    Short interframe spaces (SIFS), which are 10  long •    Point interframe spaces (PIFS), which are 30  long (SIFS + 1 [20 ] slot time..

MPLS Traffic Engineering with Autoroute

This recipe uses Cisco's Autoroute feature for managing Traffic Engineering (TE) with OSPF in an MPLS network. For this method, we must explicitly define all of the traffic paths and associate them with Tunnels on the PE routers: Router-PE1#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. Router-PE1(config)#mpls traffic-eng tunnels Router-PE1(config)#interface Loopback0 Router-PE1(config-if)#ip address 10.0.0.2 255.255.255.255 Router..