User`s manual

P-660 Series Support Notes

11. Can the P-660's SUA handle IPSec packets sent by the IPSec gateway?

Yes, the P-660's SUA can handle IPSec ESP Tunneling mode. We know when

packets go through SUA, SUA will change the source IP address and source port for

the host. To pass IPSec packets, SUA must understand the ESP packet with protocol

number 50, replace the source IP address of the IPSec gateway to the router's WAN

IP address. However, SUA should not change the source port of the UDP packets

which are used for key managements. Because the remote gateway checks this source

port during connections, the port thus is not allowed to be changed.

12. How do I setup my P-660 for routing IPSec packets over SUA?

For outgoing IPSec tunnels, no extra setting is required.

For forwarding the inbound IPSec ESP tunnel, A 'Default' server set in menu 15.2.1 is

required. It is because SUA makes your LAN appear as a single machine to the

outside world. LAN users are invisible to outside users. So, to make an internal server

for outside access, we must specify the service port and the LAN IP of this server in

Menu 15. Thus SUA is able to forward the incoming packets to the requested service

behind SUA and the outside users access the server using the P-660's WAN IP

address. So, we have to configure the internal IPsec as a default server (unspecified

service port) in menu 15.2.1 when it acts a server gateway.

13. What is Traffic Shaping?

Traffic Shaping is a feature in the P-660. It allocates the bandwidth to WAN

dynamically and aims at boosting the efficiency of the bandwidth. If there are serveral

VCs in the P-660 but only one VC activated at one time, the P-660 allocates all the

Bandwidth to the VC and the VC gets full bandwidth. If another VCs are avtivated

later, the bandwidth is yield to other VCs after ward.

14. What do the parameters (PCR, SCR, MBS) mean?

Traffic shaping parameters (PCR, SCR, MBS) can be set in Menu 4 and Menu 11.6

and is valid for both incoming and outgoing direction since G.shdsl is symmetric.

Peak Cell Rate(PCR): The maximum bandwidth allocated to this connection. The

VC connection throughput is limited by PCR.

Sustainable Cell Rate(SCR): The least guaranteed bandwidth of a VC. When there

are multi-VCs on the same line, the VC throughput is guaranteed by SCR.

Maximum Burst Size(MBS): The amount of cells transmitted through this VC at the

Peak Cell Rate before yielding to other VCs. Total bandwidth of the line is dedicated

to single VC if there is only one VC on the line. However, as the other VC asking the

bandwidth, the MBS defines the maximum number of cells transmitted via this VC

with Peak Cell rate before yielding to other VCs.