262
C
HAPTER
17: C
ONFIGURING
F
RAME
R
ELAY
Frame Relay Congestion Management
Frame Relay congestion management can process the Frame Relay packets
whenever there is network congestion. It will discard the packets that are marked
with the DE flag bit. At the same time, it will notify other devices on the network
about the congestion.
Frame Relay congestion management is applied at the output interface on a Frame
Relay switched device. If there is no congestion, the router will normally forward
the Frame Relay packets without doing any special processing on them. Once
there is congestion, the packets that are marked with the DE flag bit will be
discarded. As for the forward packets to be forwarded, the router will set the
FECN flag bit in the Frame Relay packet headers to 1. As for the backward packets
on the same PVC, the router will set the BECN flag bit in the Frame Relay packet
headers to 1. If there is no backward packets to be forwarded after a certain
period, the router will automatically transmit the Q922A Test Reponse packets
with the BECN flag bit 1 to the calling DTE.
Figure 87
Frame Relay congestion management
Frame Relay DE rule list
In a Frame Relay network, the packets that are marked with DE flag bit will be first
discarded once there is congestion. The DE rule lists are applied on the Frame
Relay PVCs on a router, and each of them contains multiple DE rules. If a packet
transmitted on a PVC complies with the rules in the DE rule list, its DE flag bit will
be set to 1, and the packets like it will be discarded first if the congestion occurs
on the network.
Configure Frame Relay
class
The 3Com Router system integrates the QoS on Frame Relay PVCs into Frame
Relay class. Thereby, it provides a flexible overall solution to Frame Relay traffic
control and quality service. Before configuring the QoS such as Frame Relay traffic
shaping, you need to create a Frame Relay class, and configure various QoS
parameters on it. Such a Frame Relay class equals to a set of QoS network service
solution. Then, the user can associate it with a Frame Relay PVC. It is equivalent to
applying a set of QoS scheme to the Frame Relay PVC. Different PVCs can use
different Frame Relay classes as well as a single Frame Relay class.
Frame Relay class configuration includes:
■
Create a Frame Relay class
■
Associate the Frame Relay class with the Frame Relay interface or a PVC
■
Configure the Frame Relay class parameters
1
Create a Frame Relay class
Perform the following configurations in system view.
Frame-relay network
Router B
Router A
DTE
NNI
DCE
BECN
FECN
Data flow direction
Summary of Contents for 3036
Page 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Page 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Page 6: ...2 ABOUT THIS GUIDE ...
Page 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
Page 8: ...4 ...
Page 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
Page 34: ...30 ...
Page 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Page 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
Page 110: ...106 ...
Page 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Page 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
Page 168: ...164 ...
Page 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Page 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
Page 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
Page 320: ...316 ...
Page 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Page 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Page 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Page 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
Page 408: ...404 ...
Page 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Page 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Page 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
Page 502: ...498 ...
Page 508: ...504 CHAPTER 33 IP MULTICAST ...
Page 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
Page 526: ...522 CHAPTER 36 CONFIGURING PIM SM ...
Page 528: ...524 ...
Page 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Page 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Page 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Page 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
Page 600: ...596 ...
Page 638: ...634 CHAPTER 43 CONFIGURING L2TP ...
Page 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
Page 650: ...646 ...
Page 666: ...662 ...
Page 670: ...666 CHAPTER 47 QOS OVERVIEW ...
Page 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Page 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Page 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
Page 708: ...704 ...
Page 762: ...758 CHAPTER 52 CONFIGURING MODEM ...