PDF user manual for CopperEdge 150

2. The CE150 forwards the request to the upstream WANVC or router, which is responsible for responding to orrelaying the request to the upstream DHCP server.Netmodel=Cross-Connect, VWAN, HDIA, or CopperVPNA CPE ( CMCP or non-CMCP)or premise LAN Host sends aDHCP request.The CE forwards the DHCPrequest to an upstream router.The router sends the DHCP requestto an upstream DHCP Server.CPELink to DSL PII:1.4.1.0CopperEdgeDSLAMUpstreamRouterDHCPServerHostDepending on the netmodel, the CEunicasts, broadcasts, or forwards theDHCP response to the CPE or Host.The DHCP Server responds withan IP address and any otherconfiguration parameters, sendingthem back to the CE.The CE150 as a DHCP Forwarding AgentPass Through ModeIf the CE150 receives a DHCP request and there is no entry inthe cmDHCPTable for that DSL PII, the CE150 passes the requestto the upstream router or DHCP server. The DHCP requestis not modified (the Relay Agent Information and ClientIdentifier fields are not inserted in the message).When the netmodel is Cross-Connect, VWAN, HDIA, or Copper-VPN, the CPE or premise LAN host can obtain an IP addressfrom the upstream DHCP server. There is enough informationin the message for the CE150 to forward the response to thecorrect DSL PII and ultimately to the correct CPE or premiseLAN host.'RZQVWUHDP'+&33URFHVVLQJIn the downstream direction, the following DHCP processingtakes place for DHCP Response messages for the various netmodels.The CE150 will drop any DHCP requests coming downstreamfrom a WAN VC or an Ethernet port.IP NetmodelThe DHCP response is routed to the DSL PII based on the IP addressof that DSL PII and the assigned Client IP address of thereceived DHCP response. The DHCP response is either broadcastdownstream on the DSL PII or sent as a unicast packetbased on the DHCP broadcast flag.&RSSHU(GJH,QVWDOODWLRQDQG2SHUDWLQJ*XLGH