I had enabled system logs, and one particular issue is notified there which may pin point to my issue:
log read
Jan 1 00:00:07 user info kernel: Calibrating delay loop... 319.48 BogoMIPS (lpj=159744)
Jan 1 00:00:07 user warn kernel: Mount-cache hash table entries: 512
Jan 1 00:00:07 user info kernel: net_namespace: 1096 bytes
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 16
Jan 1 00:00:07 user warn kernel: Total Flash size: 8192K with 128 sectors
Jan 1 00:00:07 user warn kernel: registering PCI controller with io_map_base unset
Jan 1 00:00:07 user warn kernel: registering PCI controller with io_map_base unset
Jan 1 00:00:07 user warn kernel: bio: create slab at 0
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: PME# supported from D0 D3hot
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: PME# disabled
Jan 1 00:00:07 user debug kernel: pci 0000:02:00.0: reg 10 64bit mmio: [0x000000-0x003fff]
Jan 1 00:00:07 user debug kernel: pci 0000:02:00.0: supports D1 D2
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: PCI bridge, secondary bus 0000:02
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: IO window: disabled
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: MEM window: 0x10f00000-0x10ffffff
Jan 1 00:00:07 user info kernel: pci 0000:01:00.0: PREFETCH window: disabled
Jan 1 00:00:07 user warn kernel: PCI: Enabling device 0000:01:00.0 (0000 -> 0002)
Jan 1 00:00:07 user debug kernel: PCI: Setting latency timer of device 0000:01:00.0 to 64
Jan 1 00:00:07 user warn kernel: BLOG v2.1 Initialized
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 8
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 20
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 2
Jan 1 00:00:07 user info kernel: IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
Jan 1 00:00:07 user info kernel: TCP established hash table entries: 1024 (order: 1, 8192 bytes)
Jan 1 00:00:07 user info kernel: TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
Jan 1 00:00:07 user info kernel: TCP: Hash tables configured (established 1024 bind 1024)
Jan 1 00:00:07 user info kernel: TCP reno registered
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 1
Jan 1 00:00:07 user info kernel: squashfs: version 4.0 (2009/01/31) Phillip Lougher
Jan 1 00:00:07 user info kernel: squashfs: version 4.0 with LZMA457 ported by BRCM
Jan 1 00:00:07 user info kernel: msgmni has been set to 55
Jan 1 00:00:07 user info kernel: io scheduler noop registered (default)
Jan 1 00:00:07 user warn kernel: pcieport-driver 0000:01:00.0: device [14e4:6328] has invalid IRQ; check vendor BIOS
Jan 1 00:00:07 user debug kernel: PCI: Setting latency timer of device 0000:01:00.0 to 64
Jan 1 00:00:07 user info kernel: PPP generic driver version 2.4.2
Jan 1 00:00:07 user info kernel: PPP Deflate Compression module registered
Jan 1 00:00:07 user info kernel: PPP BSD Compression module registered
Jan 1 00:00:07 user info kernel: MPPE/MPPC encryption/compression module registered
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 24
Jan 1 00:00:07 user warn kernel: bcm963xx_mtd driver v1.0
Jan 1 00:00:07 user warn kernel: File system address: 0xb8010100
Jan 1 00:00:07 user warn kernel: brcmboard: brcm_board_init entry
Jan 1 00:00:07 user warn kernel: SES: Button Interrupt 0x1 is enabled
Jan 1 00:00:07 user warn kernel: SES: LED GPIO 0x8009 is enabled
Jan 1 00:00:07 user info kernel: Serial: BCM63XX driver $Revision: 3.00 $
Jan 1 00:00:07 user info kernel: ttyS0 at MMIO 0xb0000100 (irq = 36) is a BCM63XX
Jan 1 00:00:07 user info kernel: ttyS1 at MMIO 0xb0000120 (irq = 36) is a BCM63XX
Jan 1 00:00:07 user warn kernel: bcmxtmrt: Broadcom BCM6328B0 ATM/PTM Network Device v0.3 Mar 30 2012 15:25:47
Jan 1 00:00:07 user warn kernel: Broadcom Logger v0.1 Mar 30 2012 15:24:34
Jan 1 00:00:07 user warn kernel: Mirror/redirect action on
Jan 1 00:00:07 user warn kernel: u32 classifier
Jan 1 00:00:07 user warn kernel: input device check on
Jan 1 00:00:07 user warn kernel: Actions configured
Jan 1 00:00:07 user info kernel: TCP cubic registered
Jan 1 00:00:07 user info kernel: Initializing XFRM netlink socket
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 10
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 17
Jan 1 00:00:07 user info kernel: NET: Registered protocol family 15
Jan 1 00:00:07 user info kernel: ing MCPD Module
Jan 1 00:00:07 user info kernel: Ebtables v2.0 registered
Jan 1 00:00:07 user info kernel: ebt_time registered
Jan 1 00:00:07 user info kernel: ebt_ftos registered
Jan 1 00:00:07 user info kernel: ebt_wmm_mark registered
Jan 1 00:00:07 user info kernel: 802.1Q VLAN Support v1.8 Ben Greear
Jan 1 00:00:07 user info kernel: All bugs added by David S. Miller
Jan 1 00:00:07 user warn kernel: VFS: Mounted root (squashfs filesystem) readonly on device 31:0.
Jan 1 00:00:07 user info kernel: Freeing unused kernel memory: 120k freed
Jan 1 00:00:07 user warn kernel: pktflow: module license 'Proprietary' taints kernel.
Jan 1 00:00:07 user warn kernel: Disabling lock debugging due to kernel taint
Jan 1 00:00:07 user warn kernel: Broadcom Packet Flow Cache Char Driver v2.1 Mar 18 2010 21:39:51 Registered<242>
Jan 1 00:00:07 user warn kernel: NBUFF v1.0 Initialized
Jan 1 00:00:07 user warn kernel: Broadcom Packet Flow Cache learning via BLOG enabled.
Jan 1 00:00:07 user warn kernel: Created Proc FS /procfs/fcache
Jan 1 00:00:07 user warn kernel: Broadcom Packet Flow Cache registered with netdev chain
Jan 1 00:00:07 user warn kernel: Constructed Broadcom Packet Flow Cache v2.1 Mar 18 2010 21:39:50
Jan 1 00:00:07 user warn kernel: bcmxtmcfg: bcmxtmcfg_init entry
Jan 1 00:00:07 user warn kernel: adsl: adsl_init entry
Jan 1 00:00:07 user warn kernel: Broadcom BCM6328B0 Ethernet Network Device v0.1 Mar 30 2012 15:24:40
Jan 1 00:00:07 user warn kernel: dgasp: kerSysRegisterDyingGaspHandler: bcmsw registered
Jan 1 00:00:07 user warn kernel: map:0xf,eth3: MAC Address: AC:F1:DF:F4:74:C7,VPORT_ID:1 PHY_ID:1
Jan 1 00:00:07 user warn kernel: map:0x7,eth2: MAC Address: AC:F1:DF:F4:74:C7,VPORT_ID:2 PHY_ID:2
Jan 1 00:00:07 user warn kernel: map:0x3,eth1: MAC Address: AC:F1:DF:F4:74:C7,VPORT_ID:3 PHY_ID:3
Jan 1 00:00:07 user warn kernel: map:0x1,eth0: MAC Address: AC:F1:DF:F4:74:C7,VPORT_ID:4 PHY_ID:4
Jan 1 00:00:07 user warn kernel: PCI: Enabling device 0000:02:00.0 (0000 -> 0002)
Jan 1 00:00:07 user debug kernel: PCI: Setting latency timer of device 0000:02:00.0 to 64
Jan 1 00:00:07 user warn kernel: wl:srom not detected,using main memory mapped srom info(wombo board)
Jan 1 00:00:07 user warn kernel: wl:loading /etc/wlan/bcm4313_map.bin
Jan 1 00:00:07 user warn kernel: wl0: Broadcom BCM4313 802.11 Wireless Controller 5.60.120.3.cpe4.406.0
Jan 1 00:00:07 user warn kernel: dgasp: kerSysRegisterDyingGaspHandler: wl0 registered
Jan 1 00:00:07 user info kernel: Broadcom 802.1Q VLAN Interface, v0.1
Jan 1 00:00:07 user info kernel: ip_tables: (C) 2000-2006 Netfilter Core Team
Jan 1 00:00:07 user info kernel: device eth3 entered promiscuous mode
Jan 1 00:00:08 user info kernel: ADDRCONF(NETDEV_UP): eth3: link is not ready
Jan 1 00:00:08 user info kernel: ip6_tables: (C) 2000-2006 Netfilter Core Team
Jan 1 00:00:09 user info kernel: device eth2 entered promiscuous mode
Jan 1 00:00:09 user info kernel: ADDRCONF(NETDEV_UP): eth2: link is not ready
Jan 1 00:00:10 user info kernel: device eth1 entered promiscuous mode
Jan 1 00:00:10 user info kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Jan 1 00:00:10 user info kernel: device eth0 entered promiscuous mode
Jan 1 00:00:10 user info kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready
Jan 1 00:00:11 user info kernel: device wl0 entered promiscuous mode
Jan 1 00:00:12 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:12 user warn kernel: BcmAdsl_Initialize=0xC00D7234, g_pFnNotifyCallback=0xC00FF654
Jan 1 00:00:12 user warn kernel: pSdramPHY=0xA1FFFFF8, 0x1B776E 0xDEADBEEF
Jan 1 00:00:13 user warn kernel: *** PhySdramSize got adjusted: 0x7AB04 => 0x90698 ***
Jan 1 00:00:13 user warn kernel: AdslCoreSharedMemInit: shareMemAvailable=457024
Jan 1 00:00:13 user warn kernel: AdslCoreHwReset: pLocSbSta=80fc0000 bkupThreshold=1600
Jan 1 00:00:13 user warn kernel: AdslCoreHwReset: AdslOemDataAddr = 0xA1F711A8
Jan 1 00:00:13 user warn kernel: dgasp: kerSysRegisterDyingGaspHandler: dsl0 registered
Jan 1 00:00:13 user info kernel: monitor task is initialized pid= 189
Jan 1 00:00:14 user info kernel: device wl0 left promiscuous mode
Jan 1 00:00:14 user info kernel: br0: port 5(wl0) entering disabled state
Jan 1 00:00:14 user info kernel: device wl0 entered promiscuous mode
Jan 1 00:00:14 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:14 user info kernel: br0: port 5(wl0) entering disabled state
Jan 1 00:00:14 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:15 user crit kernel: Line 0: xDSL G.994 training
Jan 1 00:00:15 user info kernel: wl0.1 (): not using net_device_ops yet
Jan 1 00:00:15 user info kernel: wl0.2 (): not using net_device_ops yet
Jan 1 00:00:15 user info kernel: wl0.3 (): not using net_device_ops yet
Jan 1 00:00:15 user info kernel: br0: port 5(wl0) entering disabled state
Jan 1 00:00:16 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:16 user info kernel: device wl0 left promiscuous mode
Jan 1 00:00:16 user info kernel: br0: port 5(wl0) entering disabled state
Jan 1 00:00:16 user info kernel: device wl0 entered promiscuous mode
Jan 1 00:00:16 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:16 user info kernel: br0: port 5(wl0) entering disabled state
Jan 1 00:00:16 user info kernel: br0: port 5(wl0) entering forwarding state
Jan 1 00:00:26 user info kernel: dhcpd uses obsolete (PF_INET,SOCK_PACKET)
Jan 1 00:00:29 user crit kernel: Line 0: ADSL G.992 started
Jan 1 00:00:31 user crit kernel: Line 0: ADSL link down
Jan 1 00:00:32 user crit kernel: Line 0: xDSL G.994 training
Jan 1 00:00:47 user crit kernel: Line 0: ADSL G.992 started
Jan 1 00:00:51 user crit kernel: Line 0: ADSL G.992 channel analysis
Jan 1 00:00:55 user crit kernel: Line 0: ADSL G.992 message exchange
Jan 1 00:00:56 user crit kernel: Line 0: ADSL link up, Bearer 0, us=999, ds=10876
Jan 1 00:00:56 user warn kernel: bcmxtmcfg: XTM Link Information, portid = 0, State = UP, Service Support = ATM
Jan 1 00:00:56 user warn kernel: bcmxtmrt: MAC address: ac f1 df f4 74 c9
Jan 1 00:00:56 user warn kernel: [DoCreateDeviceReq.2300]: register_netdev
Jan 1 00:00:56 user warn kernel: [DoCreateDeviceReq.2302]: register_netdev done
Jan 1 00:00:56 user warn kernel: bcmxtmcfg: Connection UP, LinkActiveStatus=0x1, US=999000, DS=10876000
Jan 1 00:00:56 daemon notice syslog: pppd 2.4.1 started by admin, uid 0
Jan 1 00:00:56 daemon notice syslog: PPP: Start to connect ...
Jan 1 00:00:58 daemon crit syslog: PPP server detected.
Jan 1 00:00:58 daemon crit syslog: PPP session established.
Jan 1 00:01:01 daemon crit syslog: PPP LCP UP.
Jan 1 00:01:02 daemon crit syslog: Received valid IP address from server. Connection UP.
Jan 1 00:01:02 user warn kernel: Netfilter messages via NETLINK v0.30.
Jan 1 00:01:03 user warn kernel: nf_conntrack version 0.5.0 (496 buckets, 1984 max)
Jan 1 00:02:35 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=193.169.86.30 DST=103.20.28.21 LEN=40 TOS=0x00 PREC=0x00 TTL=246 ID=54321 PROTO=TCP SPT=39199 DPT=23 WINDOW=65535 RES=0x00 SYN URGP=0 MARK=0x8000000
Jan 1 00:03:59 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=59.51.114.47 DST=103.20.28.21 LEN=40 TOS=0x00 PREC=0x00 TTL=103 ID=256 PROTO=TCP SPT=6000 DPT=8080 WINDOW=16384 RES=0x00 SYN URGP=0 MARK=0x8000000
Jan 1 00:06:04 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=111.35.36.210 DST=103.20.28.21 LEN=60 TOS=0x00 PREC=0xE0 TTL=46 ID=16496 DF PROTO=TCP SPT=12181 DPT=23 WINDOW=5808 RES=0x00 SYN URGP=0 MARK=0x8000000
Jan 1 00:06:07 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=111.35.36.210 DST=103.20.28.21 LEN=60 TOS=0x00 PREC=0xE0 TTL=46 ID=16497 DF PROTO=TCP SPT=12181 DPT=23 WINDOW=5808 RES=0x00 SYN URGP=0 MARK=0x8000000
Jan 1 00:07:03 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=58.218.211.157 DST=103.20.28.21 LEN=40 TOS=0x00 PREC=0x00 TTL=110 ID=256 PROTO=TCP SPT=44764 DPT=8080 WINDOW=512 RES=0x00 SYN URGP=0 MARK=0x8000000
Aug 16 22:27:10 user warn kernel: bcmxtmcfg: OAM loopback response not received on VCC 1.0.4
Aug 16 22:27:33 daemon crit syslog: Clear IP addresses. PPP connection DOWN.
Aug 16 22:27:33 daemon crit syslog: Clear IP addresses. Connection DOWN.
Aug 16 22:27:34 daemon info syslog: Exit.
Aug 16 22:27:36 daemon notice syslog: pppd 2.4.1 started by admin, uid 0
Aug 16 22:27:36 daemon notice syslog: PPP: Start to connect ...
Aug 16 22:27:36 daemon crit syslog: PPP server detected.
Aug 16 22:27:36 daemon crit syslog: PPP session established.
Aug 16 22:27:39 daemon crit syslog: PPP LCP UP.
Aug 16 22:27:39 user warn kernel: bcmxtmcfg: OAM loopback response not received on VCC 1.0.4
Aug 16 22:27:39 daemon crit syslog: Received valid IP address from server. Connection UP.
Aug 16 22:28:43 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=61.160.224.128 DST=103.20.28.39 LEN=40 TOS=0x00 PREC=0x00 TTL=238 ID=54321 PROTO=TCP SPT=43521 DPT=80 WINDOW=65535 RES=0x00 SYN URGP=0 MARK=0x8000000
Aug 16 22:28:48 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=199.203.59.122 DST=103.20.28.39 LEN=48 TOS=0x00 PREC=0x00 TTL=117 ID=45208 PROTO=TCP SPT=60371 DPT=2222 WINDOW=65535 RES=0x00 SYN URGP=0 MARK=0x8000000
Aug 16 22:29:43 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=58.218.211.157 DST=103.20.28.39 LEN=40 TOS=0x00 PREC=0x00 TTL=110 ID=256 PROTO=TCP SPT=44764 DPT=8080 WINDOW=512 RES=0x00 SYN URGP=0 MARK=0x8000000
Aug 16 22:33:37 user alert kernel: Intrusion -> IN=ppp0 OUT= MAC= SRC=61.160.213.38 DST=103.20.28.39 LEN=40 TOS=0x00 PREC=0x00 TTL=110 ID=256 PROTO=TCP SPT=45577 DPT=3128 WINDOW=512 RES=0x00 SYN URGP=0 MARK=0x8000000