[Nexus One Android Development] jolinnard:
This is the log when the connection is broke. Data was off and I enabled it:

D/GSM ( 613): [GsmDCT] handleMessage msg={ what=270365 when=0 arg1=1 }
D/GSM ( 613): [GsmDCT] CMD_SET_USER_DATA_ENABLE enabled=true
D/GSM ( 613): [ApnContext:dun] setRetryCount: 0
D/GSM ( 613): [ApnContext:supl] setRetryCount: 0
D/GSM ( 613): [ApnContext:hipri] setRetryCount: 0
D/GSM ( 613): [ApnContext:default] setRetryCount: 0
D/GSM ( 613): [ApnContext:mms] setRetryCount: 0
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [GsmDCT] onTrySetupData: reason=dataEnabled
D/GSM ( 613): [GsmDCT] configureRetry: forDefault=false retryCount=0 dc={GsmDC-1: State=DcInactiveState apnSetting=null apnList= [{mApnType=hipri mState=IDLE mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=null mReason=dataDisabled mRetryCount=0 mDataEnabled=true mDependencyMet=true}] RefCount=0 cid=-1 create=-1 lastFail=-1 lastFailCause=NONE}
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [GsmDC-1] setRetryCount: 0
D/GSM ( 613): [RM] setRetryCount: 0
D/GSM ( 613): [GsmDCT] configureRetry: forDefault=false retryCount=0 dc={GsmDC-2: State=DcActiveState apnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 apnList= [] RefCount=1 cid=1 create=1346143485187 lastFail=-1 lastFailCause=NONE}
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [GsmDC-2] setRetryCount: 0
D/GSM ( 613): [RM] setRetryCount: 0
D/GSM ( 613): [ApnContext:dun] setRetryCount: 0
D/GSM ( 613): [ApnContext:supl] setRetryCount: 0
D/GSM ( 613): [ApnContext:hipri] setRetryCount: 0
D/GSM ( 613): [ApnContext:default] setRetryCount: 0
D/GSM ( 613): [ApnContext:mms] setRetryCount: 0
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [RM] resetRetryCount: 0
D/GSM ( 613): [ApnContext:hipri] set reason as dataEnabled,current state IDLE
D/GSM ( 613): [GsmDCT] trySetupData for type:hipri due to dataEnabled
D/GSM ( 613): [GsmDCT] trySetupData with mIsPsRestricted=false
D/GSM ( 613): [GsmDCT] isEmergency: result=false
D/GSM ( 613): [GsmDCT] buildWaitingApns: Preferred APN:21406:21406:[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0
D/GSM ( 613): [GsmDCT] buildWaitingApns: X added preferred apnList=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0]
D/GSM ( 613): [GsmDCT] trySetupData: Create from mAllApns : [[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0][[ApnSettingV2] Pepephone MMS, 76, 21406, mms.pepephone.com, , , 212.73.32.10, 80, , -1, mms, IP, IP, true, 0]
D/GSM ( 613): [GsmDCT] Setup watingApns : [[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0]
D/GSM ( 613): [GsmDCT] setupData: apnContext={mApnType=hipri mState=IDLE mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=null mReason=dataEnabled mRetryCount=0 mDataEnabled=true mDependencyMet=true}
D/GSM ( 613): [GsmDCT] checkForConnectionForApnContext: apnContext={mApnType=hipri mState=IDLE mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406,gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=null mReason=dataEnabled mRetryCount=0 mDataEnabled=true mDependencyMet=true} NO conn
D/GSM ( 613): [GsmDCT] findReadyDataConnection: apn string <[ApnSettingV2]Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0> dcacs.size=2
D/GSM ( 613): [GsmDCT] findReadyDataConnection: dc apn string <null>
D/GSM ( 613): [GsmDCT] findReadyDataConnection: dc apn string <[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default,IP, IP, true, 0>
D/GSM ( 613): [GsmDCT] findReadyDataConnection: found ready GsmDataConnection= dcac=GsmDC-2 dc={GsmDC-2: State=DcActiveState apnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 apnList= [] RefCount=1 cid=1 create=1346143485187 lastFail=-1 lastFailCause=NONE}
D/GSM ( 613): [GsmDCT] setupData: init dc and apnContext refCount=1
D/GSM ( 613): [ApnContext:hipri] setDataConnectionAc: old dcac=null new dcac=GsmDC-2
D/GSM ( 613): [ApnContext:hipri] setDataConnection: old dc=null new dc={GsmDC-2: State=DcActiveState apnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 apnList= [{mApnType=hipri mState=IDLE mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=GsmDC-2 mReason=dataEnabled mRetryCount=0 mDataEnabled=true mDependencyMet=true}] RefCount=1 cid=1 create=1346143485187 lastFail=-1 lastFailCause=NONE} this={mApnType=hipri mState=IDLE mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=GsmDC-2 mReason=dataEnabled mRetryCount=0 mDataEnabled=true mDependencyMet=true}
D/GSM ( 613): [ApnContext:hipri] setState: INITING, previous state:IDLE
D/GSM ( 613): [GsmDCT] isDataPossible(hipri): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=true apnContextState()=INITING
D/GSM ( 613): [GsmDCT] get active apn string for type:hipri
D/GSM ( 613): [GsmDC-2] DcActiveState msg.what=EVENT_CONNECT RefCount=2
D/GSM ( 613): [GsmDC-2] notifyConnectionCompleted at 1346143631103 cause=NONE
D/GSM ( 613): [GsmDCT] setupData: initing!
D/GSM ( 613): [GsmDCT] notifyOffApnOfAvailability type:dun
D/GSM ( 613): [GsmDCT] isDataPossible(dun): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=false apnContextState()=IDLE
D/GSM ( 613): [GsmDCT] get active apn string for type:dun
D/GSM ( 613): [GsmDCT] notifyOffApnOfAvailability type:supl
D/GSM ( 613): [GsmDCT] isDataPossible(supl): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=false apnContextState()=IDLE
D/GSM ( 613): [GsmDCT] get active apn string for type:supl
D/GSM ( 613): [GsmDCT] notifyOffApnsOfAvailability skipped apn due to isReady==false: {mApnType=hipri mState=INITING mWaitingApns=[[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0] mWaitingApnsPermanentFailureCountDown=1 mApnSetting=[ApnSettingV2] Pepephone Internet, 75, 21406, gprsmov.pepephone.com, , , , , , -1, default, IP, IP, true, 0 mDataConnectionAc=GsmDC-2 mReason=dataEnabled mRetryCount=0 mDataEnabled=true mDependencyMet=true}
D/GSM ( 613): [GsmDCT] notifyOffApnOfAvailability type:default
D/GSM ( 613): [GsmDCT] isDataPossible(default): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=false apnContextState()=IDLE
D/GSM ( 613): [GsmDCT] get active apn string for type:default
D/GSM ( 613): [GsmDCT] notifyOffApnOfAvailability type:mms
D/GSM ( 613): [GsmDCT] isDataPossible(mms): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=false apnContextState()=IDLE
D/GSM ( 613): [GsmDCT] get active apn string for type:mms
D/GSM ( 613): [GsmDCT] handleMessage msg={ what=270336 when=-72ms arg1=1 obj=android.os.AsyncResult@41f23290 }
D/GSM ( 613): [GsmDCT] isDataSetupCompleteOk return true
D/GSM ( 613): [GsmDCT] onDataSetupComplete: success apn=gprsmov.pepephone.com
D/GSM ( 613): [GsmDCT] notifyDefaultData: type=hipri, reason:dataEnabled
D/GSM ( 613): [ApnContext:hipri] setState: CONNECTED, previous state:INITING
D/GSM ( 613): [GsmDCT] return link properites for hipri
D/GSM ( 613): [GsmDCT] get active pdp is not null, return link Capabilities for hipri
D/GSM ( 613): [GsmDCT] isDataPossible(hipri): possible=true isDataAllowed=true apnTypePossible=true apnContextisEnabled=true apnContextState()=CONNECTED
D/GSM ( 613): [GsmDCT] get active apn string for type:hipri
D/GSM ( 613): [GsmDCT] overall state is CONNECTED
D/GSM ( 613): [GsmDCT] startNetStatPoll
D/GSM ( 613): [ApnContext:hipri] setRetryCount: 0
D/GSM ( 613): [GsmDC-2] setRetryCount: 0
D/GSM ( 613): [RM] setRetryCount: 0
D/GSM ( 613): [GsmDCT] handleMessage msg={ what=270368 when=-1ms arg1=1 }
D/RILJ ( 613): [1140]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1141]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1140]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@44] [138@37]
D/RILJ ( 613): [1141]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@44] [138@37]
D/GSM ( 613): [GsmDCT] handleMessage msg={ what=270368 when=0 arg1=1 }
D/RILJ ( 613): [1142]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1142]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@40] [138@38]
D/RILJ ( 613): [1143]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1143]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@40] [138@38]
D/RILJ ( 613): [1144]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1144]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@40] [138@38]
D/RILJ ( 613): [1145]> REQUEST_GET_NEIGHBORING_CELL_IDS
D/RILJ ( 613): [1145]< REQUEST_GET_NEIGHBORING_CELL_IDS [1b@40] [138@38]
D/GSM ( 613): [GsmDCT] onReceive: action=com.android.internal.telephony.gprs-data-stall
D/GSM ( 613): [GsmDCT] handleMessage msg={ what=270353 when=0 arg1=95228 obj=com.android.internal.telephony.gprs-data-stall }

And a screenshot of the Testing tool:

http://i.imgur.com/iGhTk.png