Introduction 1-17
Network Management
ForeSight monitors each path in the forward direction to detect any point where congestion may
occur and returns the information back to the entry to the network. When spare capacity exists with
the network, ForeSight permits the extra bandwidth to be allocated to active virtual circuits. Each
PVC is treated fairly by allocating the extra bandwidth based on each PVC's committed bandwidth
parameter.
If the network reaches full utilization, ForeSight detects this and quickly acts to reduce the extra
bandwidth allocated to the active PVCs. ForeSight reacts quickly to network loading in order to
prevent dropped packets. Periodically, each node automatically measures the delay experienced
along a frame relay PVC. This delay factor is used in calculating the ForeSight algorithm.
With basic frame relay service, only a single rate parameter can be specified for each PVC. With
ForeSight, the virtual circuit rate can be specified based on a minimum, maximum, and initial
transmission rate for more flexibility in defining the frame relay circuits.
ForeSight provides effective congestion management for PVC's traversing broadband ATM as well.
ForeSight operates at the cell-relay level that lies below the frame relay services provided by the IPX
switch and IGX switch. With the queue sizes utilized in the BPX switch, the bandwidth savings is
approximately the same as experienced with lower speed trunks. When the cost of these lines is
considered, the savings offered by ForeSight can be significant.
Network Management
BPX switches provide one high-speed and two low-speed data interfaces for data collection and
network management. The high-speed interface is an Ethernet 802.3 LAN interface port for
communicating with a Cisco StrataView Plus NMS workstation. TCP/IP provides the transport and
network layer, Logical Link Control 1 is the protocol across the Ethernet port.
The low-speed interfaces are two RS-232 ports, one for a network printer and the second for either
a modem connection or a connection to an external control terminal. These low-speed interfaces are
the same as provided by the IPX switch and IGX switch.
A Cisco StrataView Plus NMS workstation connects via the Ethernet to the LAN port on the BPX
and provides network management via SNMP. Statistics are collected by Cisco StrataView Plus
using the TFTP protocol. On IPX switch and IGX switch shelves, frame relay connections are
managed via the Cisco StrataView Plus Connection Manager. On MGX 8220 shelves, the Cisco
StrataView Plus Connection Manager manages frame relay and ATM connections, and the
Connection Manager is used for MGX 8220 shelf configuration.
Each BPX switch can be configured to use optional low-speed modems for inward access by the
Cisco Technical Response Team for network troubleshooting assistance or to autodial Customer
Service to report alarms remotely. If desired, another option is remote monitoring or control of
customer premise equipment through a window on the Cisco StrataView Plus workstation.
Network Interfaces
Network interfaces connect the BPX switch to other BPX, IGX, or IPX switches to form a wide-area
network.
The BPX switch provides T3, E3, OC3/STM-1, and OC12/STM-4 trunk interfaces. The T3 physical
interface utilizes DS3 C-bit parity and the 53-byte ATM physical layer cell relay transmission using
the Physical Layer Convergence Protocol. The E3 physical interface uses G.804 for cell delineation
and HDB3 line coding. The BNI-155 card supports single-mode fiber (SMF), single-mode fiber long
reach (SMF-LR), and multi-mode fiber (MMF) physical interfaces. The BXM-155 cards support
SMF, SMFLR, and MMF physical interfaces. The BXM-622 cards support SMF and SMFLR
physical interfaces.
