Looking at the trace, it seems like we are seeing some application drop errors for SIP when traffic is coming from the provider to the SRX:
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:<providerSIP.247.103/5060->publicIP.143.3/18138;17> matched filter provider:
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:packet [365] ipid = 0, @423f7c9e
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:---- flow_process_pkt: (thd 1): flow_ctxt type 13, common flag 0x0, mbuf 0x423f7b00, rtbl_idx = 20416
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow process pak fast ifl 69 in_ifp fe-0/0/2.0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: find flow: table 0x4d6bc358, hash 45133(0xffff), sa providerSIP.247.103, da publicIP.143.3, sp 5060, dp 18138, proto 17, tok 448
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_create_session
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:RM populated xlate info for nsp2: local.12.1/5060->providerSIP.247.103/5060out_ifp = fe-0/0/4.0, out_tunnel = 0x0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_in_dst_nat: in <fe-0/0/2.0>, out <fe-0/0/4.0> dst_adr publicIP.143.3, sp 5060, dp 18138
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_in_dst_nat: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_rule_dst_xlate: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_routing: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_policy_search: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_reverse_mip: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_src_xlate: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_get_out_ifp: bypassed by RM
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:is_loop_pak: No loop: on ifp: fe-0/0/4.0, addr: local.12.1, rtt_idx:0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:policy is NULL (wx/pim scenario)
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sm_flow_interest_check: app_id 0, policy 10, app_svc_en 0, flags 0x2. not interested
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sm_flow_interest_check: app_id 1, policy 10, app_svc_en 0, flags 0x2. not interested
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sm_flow_interest_check: app_id 2, policy 10, app_svc_en 0, flags 0x2. interested
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:flow_do_sm_interest_check: natp 0x4ce178d0, app_id 63, ALG & SZ vectors set, SZ 0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: service lookup identified service 63.
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_final_check: in <fe-0/0/2.0>, out <fe-0/0/4.0>
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:flow_first_final_check: flow_set_xlate_vector.
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: existing vector list 1080-446c8ae8.
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: Session (id:52264) created for first pak 1080
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow_first_install_session======> 0x4ce178d0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: nsp 0x4ce178d0, nsp2 0x4ce1793c
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: make_nsp_ready_no_resolve()
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: route lookup: dest-ip providerSIP.247.103 orig ifp fe-0/0/2.0 output_ifp fe-0/0/2.0 orig-zone 7 out-zone 7 vsd 0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: route to publicIP.143.6
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:Installing c2s NP session wing
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:Installing s2c NP session wing
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sm_flow_notify_session_creation: app_id 2, flags 0x0, ifl_in 69, zone_in 7, ifl_out 71, zone_out 8
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow got session.
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: flow fast tcp/udp session id 52264
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:flow_alg_vector(): VECTOR: pak_ptr(0x3fdedc70.0x423f7b00): natp(0x4ce178d0).nsp(0x4ce178d0): app_id: 63, flag: 0x00000003.
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip:
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip: ------------------sip vector entry -----------------
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg..... packet received (providerSIP.247.103 -> publicIP.143.3) len=365
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg..... udp packet received (5060 -> 18138) len=337, cksum=0x5854
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg/call Dialog dlg0x457c69cc received provisional 100 ((null))
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg/call ALG action 2
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg/call Dialog dlg0x457c8aa4 sending provisional 100 ((null))
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip_alg..... packet sent (providerSIP.247.103 -> publicIP.143.3) len=472
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:sip: sip alg vector finish successfully ret = 0
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT:flow_alg_vector: status -1
Aug 4 13:04:51 13:04:50.1161249:CID-0:RT: packet dropped, sm application error
But I also see some H323 packets seeing TTL expired error. I thought you are using SIP?
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT:<local.10.21/3152->local.12.1/1720;6> matched filter avaya:
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT:packet [40] ipid = 1743, @423e861e
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT:---- flow_process_pkt: (thd 1): flow_ctxt type 13, common flag 0x0, mbuf 0x423e8480, rtbl_idx = 20416
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: flow process pak fast ifl 70 in_ifp fe-0/0/3.0
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: fe-0/0/3.0:local.10.21/3152->local.12.1/1720, tcp, flag 10
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: find flow: table 0x4d6bc358, hash 23999(0xffff), sa local.10.21, da local.12.1, sp 3152, dp 1720, proto 6, tok 384
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: flow got session.
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: flow session id 51516
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT:flow_asp_vector tcp_proxy_inbound_handler, returned the packet m 0x423e8480, 13.
Aug 4 13:04:51 13:04:50.1177290:CID-0:RT: ----- flow_process_pkt rc 0x7 (fp rc 5)
Aug 4 13:04:51 13:04:50.1600294:CID-0:RT: encap vector
Aug 4 13:04:51 13:04:50.1600294:CID-0:RT: no more encapping needed
Aug 4 13:04:51 13:04:50.1600294:CID-0:RT: **** pak processing end.
Aug 4 13:04:51 13:04:50.1600294:CID-0:RT:flow_first_complete_session: Sending icmp for ttl expiry
Aug 4 13:04:51 13:04:50.1600294:CID-0:RT: packet dropped, ttl expiry