RS8234EBGC Mindspeed Technologies, RS8234EBGC Datasheet - Page 179

• Manufacturer Part Number: RS8234EBGC
• Description: RS8234EBGC ATM XBR SAR
• Manufacturer: Mindspeed Technologies

RS8234
ATM ServiceSAR Plus with xBR Traffic Management
28234-DSH-001-B
APPLICATION EXAMPLES: Tunnels
a fixed number of Schedule table slots to the tunnel to reserve a fixed rate. Each time an assigned slot is
encountered by the Cell Scheduler, it selects a VCC from a round-robin queue of active VCCs assigned to
that priority.
CBR bandwidth assigned to the tunnel. Tunneling enables system-level end users to purchase CBR services
from a WAN service provider. The purchaser can then dynamically manage the traffic within this leased CBR
tunnel as CBR and/or a combination of other service categories.
priority five, is through a private ATM network, perhaps a corporate ATM campus backbone. The other
tunnel, priority six, carries traffic through a public network. This topology allows the end user to lease
reserved CBR bandwidth from an administrative domain, but manage the usage of the tunnel in an arbitrary
fashion.
tunnels or pipes. Each can have an equal 1/4 share of the bandwidth available to the port by provisioning
every fourth schedule table slot to one tunnel for each of the four tunnels.
real-time VBR, the next highest priority to non-real-time VBR, the third highest priority to ABR, and the
lowest priority to UBR. This in effect establishes four multi-service pipes, each on equal priority to the others
(since the scheduler services each of the four pipes equally). Thus, the 4 rt-VBR priorities have effectively
the same priority, and so on through the four levels of priority serviced in each pipe. Number of VBR/ABR
priorities is 12. CBR_TUN = 1, SLOT_DEPTH = 110.
Highest VBR/ABR Scheduling priority is 15 (that is, PRI = 15). Thus, VBR_OFFSET = 3.
Figure 6-6
For example, 100 UBR VCCs with PRI = 6 might currently be segmenting data. Each gets 1/100th of the
In this example, the user has configured the RS8234 to manage two independent tunnels. The first tunnel
Figure 6-11
In each of the tunnels, 4 priority levels are assigned. The highest priority in each tunnel is assigned to
shows priorities five and six used as CBR tunnels for UBR and VBR traffic. The host assigns
illustrates a different use of CBR tunnels. In this example, the user has established 4 separate
Mindspeed Technologies
™
6.2 xBR Cell Scheduler Functional Description
6.0 Traffic Management
6-19