Avaya Configuring Frame Relay Services Bedienungsanleitung Seite 23

  • Herunterladen
  • Zu meinen Handbüchern hinzufügen
  • Drucken
  • Seite
    / 94
  • Inhaltsverzeichnis
  • LESEZEICHEN
  • Bewertet. / 5. Basierend auf Kundenbewertungen
Seitenansicht 22
Frame Relay Overview
117376-A Rev. A
2-3
Frame Relay Packets
Figure 2-2 illustrates the structure of a frame relay packet. The packet’s header
field includes the following:
Data link connection identifier (DLCI)
The DLCI is the permanent virtual circuit (PVC) identification number. The
frame relay network uses the DLCI to direct basic data flow.
Command/response bit (C/R)
ITU-T (formerly CCITT) standards do not use this bit.
Forward explicit congestion notification (FECN) and backward explicit
congestion notification (BECN)
The FECN and BECN indicate congestion on the network. See “Congestion
Control,” on page 2-
14 for information about how the frame relay software
uses these bits.
Discard eligibility (DE)
The DE bit allows the router to mark specific frames as low priority (discard
eligible) before transmitting them to the frame relay network.
Extended address bit (EA)
The EA bit signals whether the next byte is part of the address. This bit
indicates the last byte of the DLCI.
Figure 2-2. Frame Relay Header, 2-Byte Format
DLCI (high order) C/R
DE
EA
F
E
C
N
DLCI (low order)
8 7 6 5 4 3 2 1
B
E
C
N
Flag
Frame
relay
header
Information
(data)
CRC
Flag
EA
FR0002A
Seitenansicht 22
1 2 ... 18 19 20 21 22 23 24 25 26 27 28 ... 93 94

Kommentare zu diesen Handbüchern

Keine Kommentare