Here follow debug ppp negotiation on the 5300 side
17w1d: As38 PPP: Treating connection as a callin
17w1d: As38 PPP: Phase is ESTABLISHING, Passive Open
17w1d: As38 LCP: State is Listen
17w1d: As38 LCP: I CONFREQ [Listen] id 1 len 20
17w1d: As38 LCP: ACCM 0x00000000 (0x020600000000)
17w1d: As38 LCP: MagicNumber 0x3C3D77EB (0x05063C3D77EB)
17w1d: As38 LCP: PFC (0x0702)
17w1d: As38 LCP: ACFC (0x0802)
17w1d: As38 LCP: O CONFREQ [Listen] id 77 len 25
17w1d: As38 LCP: ACCM 0x000A0000 (0x0206000A0000)
17w1d: As38 LCP: AuthProto CHAP (0x0305C22305)
17w1d: As38 LCP: MagicNumber 0x3B371CA3 (0x05063B371CA3)
17w1d: As38 LCP: PFC (0x0702)
17w1d: As38 LCP: ACFC (0x0802)
17w1d: As38 LCP: O CONFACK [Listen] id 1 len 20
17w1d: As38 LCP: ACCM 0x00000000 (0x020600000000)
17w1d: As38 LCP: MagicNumber 0x3C3D77EB (0x05063C3D77EB)
17w1d: As38 LCP: PFC (0x0702)
17w1d: As38 LCP: ACFC (0x0802)
17w1d: As38 LCP: I CONFACK [ACKsent] id 77 len 25
17w1d: As38 LCP: ACCM 0x000A0000 (0x0206000A0000)
17w1d: As38 LCP: AuthProto CHAP (0x0305C22305)
17w1d: As38 LCP: MagicNumber 0x3B371CA3 (0x05063B371CA3)
17w1d: As38 LCP: PFC (0x0702)
17w1d: As38 LCP: ACFC (0x0802)
17w1d: As38 LCP: State is Open
17w1d: As38 PPP: Phase is AUTHENTICATING, by this end
17w1d: As38 CHAP: O CHALLENGE id 31 len 40 from "c-5300-xxxxxxxxx-1"
17w1d: As38 CHAP: I RESPONSE id 31 len 26 from "XXXXXXX (my username)"
17w1d: As38 CHAP: O SUCCESS id 31 len 4
17w1d: As38 PPP: Phase is UP
17w1d: As38 IPCP: O CONFREQ [Closed] id 24 len 10
17w1d: As38 IPCP: Address 10.1.14.250 (0x03060A010EFA)
17w1d: As38 CDPCP: O CONFREQ [Closed] id 14 len 4
17w1d: As38 IPCP: I CONFREQ [REQsent] id 1 len 28
17w1d: As38 IPCP: CompressType VJ 15 slots CompressSlotID (0x0206002D0F01)
17w1d: As38 IPCP: Address 0.0.0.0 (0x030600000000)
17w1d: As38 IPCP: PrimaryDNS 0.0.0.0 (0x810600000000)
17w1d: As38 IPCP: SecondaryDNS 0.0.0.0 (0x830600000000)
17w1d: As38 AAA/AUTHOR/IPCP: Start. Her address 0.0.0.0, we want 0.0.0.0
17w1d: As38 AAA/AUTHOR/IPCP: Says use pool NMC
17w1d: As38 AAA/AUTHOR/IPCP: Pool returned 212.XXX.XXX.251
17w1d: As38 AAA/AUTHOR/IPCP: Done. Her address 0.0.0.0, we want 212.XXX.XXX.251
17w1d: As38 IPCP: O CONFREJ [REQsent] id 1 len 16
17w1d: As38 IPCP: CompressType VJ 15 slots CompressSlotID (0x0206002D0F01)
17w1d: As38 IPCP: SecondaryDNS 0.0.0.0 (0x830600000000)
17w1d: As38 UNKNOWN(0x8057): I CONFREQ [Not negotiated] id 1 len 14
17w1d: As38 UNKNOWN(0x8057): Type1 (0x010A020A95FFFEC3CFCC)
17w1d: As38 LCP: O PROTREJ [Open] id 78 len 20 protocol UNKNOWN(0x8057) (0x80570101000E010A020A95FFFEC3CFCC)
17w1d: As38 IPCP: I CONFACK [REQsent] id 24 len 10
17w1d: As38 IPCP: Address 10.1.14.250 (0x03060A010EFA)
17w1d: As38 LCP: I PROTREJ [Open] id 2 len 10 protocol CDPCP (0x8207010E0004)
17w1d: As38 CDPCP: State is Closed
17w1d: As38 IPCP: I CONFREQ [ACKrcvd] id 2 len 16
17w1d: As38 IPCP: Address 0.0.0.0 (0x030600000000)
17w1d: As38 IPCP: PrimaryDNS 0.0.0.0 (0x810600000000)
17w1d: As38 AAA/AUTHOR/IPCP: Start. Her address 0.0.0.0, we want 212.XXX.XXX.251
17w1d: As38 AAA/AUTHOR/IPCP: Done. Her address 0.0.0.0, we want 212.XXX.XXX.251
17w1d: As38 IPCP: O CONFNAK [ACKrcvd] id 2 len 16
17w1d: As38 IPCP: Address 212.XXX.XXX.251 (0x0306XXXXXXX)
17w1d: As38 IPCP: PrimaryDNS 212.XXX.XXX.2 (0x81XXXXXXXXX)
17w1d: As38 IPCP: TIMEout: State ACKrcvd
17w1d: As38 IPCP: O CONFREQ [ACKrcvd] id 25 len 10
17w1d: As38 IPCP: Address 10.1.14.250 (0x03060A010EFA)
17w1d: As38 IPCP: I CONFREQ [REQsent] id 3 len 16
17w1d: As38 IPCP: Address 212.XXX.XXX.251 (0x0306XXXXXXX)
17w1d: As38 IPCP: PrimaryDNS 212.XXX.XXX.2 (0x810306XXXXX)
17w1d: As38 AAA/AUTHOR/IPCP: Start. Her address 212.XXX.XXX.251, we want 212.XXX.XXX.251
17w1d: As38 AAA/AUTHOR/IPCP: Request 212.XXX.XXX.251 from pool NMC
17w1d: As38 AAA/AUTHOR/IPCP: Pool grants 212.XXX.XXX.251
17w1d: As38 AAA/AUTHOR/IPCP: Done. Her address 212.XXX.XXX.251, we want 212.XXX.XXX.251
17w1d: As38 IPCP: O CONFACK [REQsent] id 3 len 16
17w1d: As38 IPCP: Address 212.XXX.XXX.251 ()
17w1d: As38 IPCP: PrimaryDNS 212.XXX.XXX.2 ()
17w1d: As38 IPCP: I CONFACK [ACKsent] id 25 len 10
17w1d: As38 IPCP: Address 10.1.14.250 (0x03060A010EFA)
17w1d: As38 IPCP: State is Open
17w1d: As38 IPCP: Install route to 212.XXX.XXX.251
17w1d: As38 LCP: I TERMREQ [Open] id 3 len 16 (0x557365722072657175657374)
17w1d: As38 LCP: O TERMACK [Open] id 3 len 4
17w1d: As38 IPCP: State is Closed
17w1d: As38 PPP: Phase is TERMINATING
17w1d: As38 IPCP: Remove route to 212.XXX.XXX.251
17w1d: As38 LCP: TIMEout: State TERMsent
17w1d: As38 LCP: State is Closed
17w1d: As38 PPP: Phase is DOWN
17w1d: As38 PPP: Phase is ESTABLISHING, Passive Open
17w1d: As38 LCP: State is Listen
17w1d: As38 LCP: State is Closed
17w1d: As38 PPP: Phase is DOWN
Hope this can add more details about my problem.
P.S. For obvious reason i tweaked IP Addresses
thanks
reactive