Chapter 9 Topology Hiding
IPv6 Support
Figure 9-1 illustrates a No NAPT media flow through the DBE between user side A and user side B.
Figure 9-1 No NAPT Media Flow
send |
| 1 | recv | send | 2 | recv | |||||
|
|
|
|
|
|
|
|
|
|
|
|
2001:10::10/1700210.10.231.8: | 822001:11::11/28988.19. 2.134:28988 | 10.10.231.8:2001:10::10/17002 822001:11::11/28988.19. 2.134:28988 | |||||||||
|
|
|
|
|
|
|
|
|
| ||
recv | 4 | send | recv | 3 | send | ||||||
|
|
|
|
|
| ||||||
|
|
|
|
|
|
|
|
|
|
| |
User Side A |
|
| DBE |
|
|
| User Side B | ||||
230526
1.User side A sends a packet from IP address and port 2001:10::10/17002 to destination address and port 2001:11::11/28988 on side B. The DBE intercepts this packet and matches it to the side A flow.
2.The DBE applies QoS policing and forwards the packet to endpoint B without changing the destination address to a DBE local media address (as is done in Single NAPT). Under No NAPT processing, the DBE does not rewrite either source or destination IP addresses and ports.
3.Side B sends a packet from IP address and port 2001:11::11/28988 to originating source address and port 2001:10::10/17002. The DBE intercepts this packet and matches it to the side B flow.
4.The DBE applies QoS policing and forwards the packet to user side A without rewriting either source or destination IP addresses and ports.
IPv6 Single NAPT for Signaling
Support of IPv6 signaling flows requires Single NAPT.
The DBE is able to translate IP addresses and port numbers in both directions of a flow. However, Single NAPT means only one IP address and port is translated. In Single NAPT processing, the flow on one side of the pinhole is programmed with a local address and port that do not belong to the SBC. Instead, that local address and port of the flow are specified by the MGC to match the remote address and port on the other side of the pinhole. Thus, incoming traffic (downstream traffic of SIP server to access side) is addressed directly to the remote endpoint and the SIP server details are hidden from subscribers. Network topology must be used to route the downstream traffic through the DBE. In one sense, Single NAPT provides
SBC rewrites destination IP address and port for packets received from the user. SBC does not rewrite source IP address and port of packets received from the user (they are unchanged from the IP address and port of the source endpoint). Correspondingly, SBC rewrites the source IP address and port of packets received from the MGC, but not the destination IP address or port.
Cisco IOS XE Integrated Session Border Controller Configuration Guide for the Cisco ASR 1000 Series Aggregation Services Routers
|
| ||
|
|
