HP 200 Series Services And Applications page 44

Branch Office Routing
Reducing Cost and Improving Robustness
Bandwidth reservation works with traffic prioritization. Protocols or data
can be prioritized, and during periods of peak WAN utilization, bandwidth
can be reserved for each priority level. The goal is to ensure that the highest
priority data receives enough bandwidth without starving applications
transmitting lower priority data.
Controlling Latency
Latency is the time a packet spends inside a router as it is forwarded and
queued for transmission. In router-based networks, the apparent time
required for an application process to execute across a network is often
determined by link propagation delay and router latency, latency being the
primary factor.
Latency can be reduced by tailoring the size of the transmit buffer queue of a
WAN link to fit the speed of the link. HP routers improve application respon-
siveness by providing network designers with precise control over the
amount of data that is buffered on WAN links, thereby reducing latency.
Reducing Cost and Improving Robustness
Once relegated to the communications backwaters, circuit switching
(dial-up) technology is becoming an increasingly attractive proposition for
branch office networking. The near universal availability of switched digital
communications (Switched 56 and/or ISDN) as well as the new CCITT V.fast
recommendation clearly put circuit switching in the mainstream as far as
bandwidth is concerned. Circuit switching can be an ideal solution both as a
primary and backup connection mechanism. HP has developed several
unique solutions using dial-up communications to help customers solve
branch office networking needs.
Dial on Demand
HP routers can use dial-up communications as the primary means by which
data is exchanged between branch offices and corporate or regional offices.
While not the ideal communication facility for transaction-oriented applica-
tions, dial-up is very cost effective for batch networking requirements such
as file transfer and electronic mail. HP routers can use both V.25 bis and
manual (DTR mode) modems, and terminal adapters.
1-40