Chapter 9 Subscriber Port Setup Screens
Management Switch Card User’s Guide
265
9.14.1 Upstream and Downstream Traffic
When the MSC forwards upstream traffic, it makes the following changes in the layer-2 header.
The original frame has the MSC’s MAC address as the destination MAC address because the MSC,
not the device that really has the destination IP, responded to the ARP request for the destination
IP. (This is part of the ARP proxy feature for IP bridges.) Once the MSC receives the frame, it
updates the MAC addresses and VLAN ID and forwards it to the device that really has the
destination IP.
This is illustrated in the following example.
Figure 169
IP Bridge: Upstream Traffic Example
Notice that the MSC does not change the IP packet header.
The process is reversed but otherwise similar for downstream traffic. The MSC learns how to
forward frames to the appropriate subscriber from one of the following sources.
• DHCP snooping. The IP-aware MSC snoops DHCP packets, so it knows what IP addresses have
been assigned to subscribers.
• ARP. The MSC uses ARP to find out which subscriber has a particular IP address.
• Static information. You should provide forwarding information manually for subscribers that have
static IP addresses and do not respond to ARP queries.
Table 119
IP Bridge: Layer-2 Header for Upstream Traffic
ORIGINAL
UPDATED
Source MAC address
Subscriber’s MAC address
MSC’s MAC address
Destination MAC address
MSC’s MAC address
Destination IP’s MAC address
VLAN ID
Subscriber’s VLAN ID
Destination IP’s VLAN ID
MAC
g
MAC
x
MAC
a
Source IP: 192.168.1.1
Source MAC:
x
Destination IP: 192.168.10.5
Destination MAC:
g
VLAN:
200
Source IP: 192.168.1.1
Source MAC: a
Destination IP: 192.168.10.5
Destination MAC: x
VLAN: 100
IP 192.168.10.5
IP: 192.168.1.1
VLAN: 100
VLAN: 200
Содержание MSC1000G Series
Страница 38: ...Table of Contents Management Switch Card User s Guide 38...
Страница 39: ...39 PART I Introduction...
Страница 40: ...40...
Страница 54: ...Chapter 1 Getting to Know Your MSC Management Switch Card User s Guide 54...
Страница 61: ...61 PART II Web Configurator...
Страница 62: ...62...
Страница 80: ...Chapter 3 The Web Configurator Management Switch Card User s Guide 80...
Страница 162: ...Chapter 5 Alarm Screens Management Switch Card User s Guide 162...
Страница 178: ...Chapter 6 Diagnostic Screens Management Switch Card User s Guide 178...
Страница 184: ...Chapter 7 Maintenance Screens Management Switch Card User s Guide 184...
Страница 204: ...Chapter 8 Multicast Screens Management Switch Card User s Guide 204...
Страница 226: ...Chapter 9 Subscriber Port Setup Screens Management Switch Card User s Guide 226...
Страница 227: ...Chapter 9 Subscriber Port Setup Screens Management Switch Card User s Guide 227...
Страница 330: ...Chapter 10 IMA Screens Management Switch Card User s Guide 330...
Страница 346: ...Chapter 11 Profile Screens Management Switch Card User s Guide 346 Figure 222 Profile VDSL2 LineProfile MIB PSD Mask...
Страница 351: ...Chapter 11 Profile Screens Management Switch Card User s Guide 351 Figure 225 Profile VDSL2 LineProfile Virtual Noise...
Страница 404: ...Chapter 11 Profile Screens Management Switch Card User s Guide 404 Figure 267 ACL Profile Setup...
Страница 412: ...Chapter 11 Profile Screens Management Switch Card User s Guide 412...
Страница 451: ...Chapter 12 Statistics Screens Management Switch Card User s Guide 451 Figure 297 Port Statistics DSL Line Card Status...
Страница 512: ...Chapter 12 Statistics Screens Management Switch Card User s Guide 512...
Страница 560: ...Chapter 13 Switch Screens Management Switch Card User s Guide 560...
Страница 598: ...Chapter 15 VLAN Screens Management Switch Card User s Guide 598...
Страница 636: ...Chapter 16 VoIP Management Switch Card User s Guide 636...
Страница 638: ...Chapter 17 Config Save Management Switch Card User s Guide 638...
Страница 639: ...639 PART III Commands...
Страница 640: ...640...
Страница 646: ...Chapter 18 Commands Management Switch Card User s Guide 646...
Страница 682: ...Chapter 19 acl Commands Management Switch Card User s Guide 682...
Страница 690: ...Chapter 20 alarm Commands Management Switch Card User s Guide 690...
Страница 696: ...Chapter 22 config Commands Management Switch Card User s Guide 696...
Страница 754: ...Chapter 28 multicast Commands Management Switch Card User s Guide 754...
Страница 840: ...Chapter 29 port Commands Management Switch Card User s Guide 840...
Страница 924: ...Chapter 30 profile Commands Management Switch Card User s Guide 924...
Страница 926: ...Chapter 31 redundant Commands Management Switch Card User s Guide 926...
Страница 1062: ...Chapter 35 vlan Commands Management Switch Card User s Guide 1062...
Страница 1103: ...1103 PART IV Troubleshooting Specifications Appendices and Index...
Страница 1104: ...1104...
Страница 1134: ...Chapter 39 Product Specifications Management Switch Card User s Guide 1134...
Страница 1146: ...Appendix B Legal Information Management Switch Card User s Guide 1146...