Pppoe - ZyXEL Communications GS3700 Series User Manual

This chapt er describes how t he Swit ch gives a PPPoE t erm inat ion server addit ional inform at ion t hat
t he server can use t o ident ify and aut hent icat e a PPPoE client .
30.1 PPPoE Intermediate Agent Overview
A PPPoE I nt erm ediat e Agent ( PPPoE I A) is deployed bet ween a PPPoE server and PPPoE client s. I t
helps t he PPPoE server ident ify and aut hent icat e client s by adding subscriber line specific
inform at ion t o PPPoE discovery packet s from client s on a per- port or per- port- per- VLAN basis
before forwarding t hem t o t he PPPoE server.
PPPoE Client
30.1.1 PPPoE Intermediate Agent Tag Format
I f t he PPPoE I nt erm ediat e Agent is enabled, t he Swit ch adds a vendor- specific t ag t o PADI ( PPPoE
Act ive Discovery I nit ializat ion) and PADR ( PPPoE Act ive Discovery Request ) packet s from PPPoE
client s. This t ag is defined in RFC 2516 and has t he following form at for t his feat ure.
Table 148 PPPoE I nt erm ediat e Agent Vendor- specific Tag Form at
Tag_Type
( 0x0105)
The Tag_Type is 0x0105 for vendor- specific t ags, as defined in RFC 2516. The Tag_Len indicat es t he
lengt h of Value, i1 and i2. The Value is t he 32- bit num ber 0x00000DE9, which st ands for t he "ADSL
Forum " I ANA ent ry. i1 and i2 are PPPoE int erm ediat e agent sub- opt ions, which cont ain addit ional
inform at ion about t he PPPoE client .
30.1.2 Sub-Option Format
There are t wo t ypes of sub- opt ion: "Agent Circuit I D Sub- opt ion" and "Agent Rem ot e I D Sub-
opt ion". They have t he following form at s.
Table 149 PPPoE I A Circuit I D Sub- opt ion Form at : User- defined St ring
SubOpt Lengt h
0x01 N
( 1 byt e) ( 1 byt e)
C
PPPoE IA
Tag_Len Value
St ring
( 63 byt es)
GS3700/XGS3700 Series User's Guide
316
HAPTER
PPPoE Server
i1 i2
Value
3 0

PPPoE