Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 942)

Page 30-4
On the receiving side, as low priority frames are being received they will be put into the
MLPPP reassembly queue, as supported by the existing software. As complete frames are
received they will be forwarded to the normal PPP processing. When high priority frames are
received, since they will always be sent complete, they will immediately be forwarded to the
normal PPP processing.
The only configurable parameter that has been added is the maximum delay. The feature is
enabled when this parameter is set to a non-zero value. A flag has been utilized to force a 16
fragment maximum for a fragmented frame to make this process compatible with Cisco
products.
The following diagram illustrates this concept:
PPP Fragmentation Process
Overview of PPP Configuration Procedures
The configuration of a PPP connection on your switch is divided into three separate tasks.
This three-phase strategy was chosen to allow PPP connections to be configured over any
serial channel interface without requiring the use of multiple PPP configuration displays for
each separate type of interface.
Step 1. Configure the Physical Interface to be Used for PPP
The information configured at the physical interface level includes the specification of the
type of WSX interface and of any information that is specific to the given type of interface.
The interfaces that can support PPP are ISDN, T1/E1, and the Universal Serial Port on all WSX
boards.
An ISDN interface (WSX-BRI) requires the specification of the switch type, the local telephone
number, and the Service Profile Identifiers (SPIDs) if appropriate for the switch type. The UI
commands used to configure ISDN interfaces allow for modifying and viewing ISDN port’s
configuration and the display of its operational status. See Chapter 32 titled “Managing ISDN
Ports” for detailed information on configuring an ISDN interface for PPP.
Higher Priority Frame Lower Priority Frame
Higher Priority Frame Lower Priority Fragment Lower Priority Fragment
Before Transmission
After Transmission
Queue
Queue