Key Responsibilities
IMS Core (Network) Responsibilities:
- Expertise in VoIP/IMS Core entities: P-CSCF, I-CSCF, S-CSCF, HSS, SLF, and VoLTE
- Deep understanding of SIP call processing and SIP Supplementary Services
- Knowledge of telecom protocols: SIP, SDP, H.248, MGCP, DIAMETER
- Understanding IMS evolution, subsystems, functionalities, and SIP service call flows
- Hands-on experience with TLS, TCP, IPSEC, and IP protocols
- Integration and troubleshooting of distributed IP architectures: soft switches, gateways, SIP proxies, route engines, IP media servers, IP phones/IADs
- Experience with IMS interworking entities: BGCF, MGCF, MRFC, MRFP, AGW, IBCF, TrGW
- Knowledge of session border controllers, NAT, firewalls, authentication, encryption, and L2 network switches (routers/switches)
- Media handling, transcoding, call modeling (CS, SMS, MMS), MGWs
- Strong analytical and log debugging skills; scripting knowledge is a plus
- Exposure to Class 4/5 switches and Unix/Linux OS
IMS Application Responsibilities:
- Deep knowledge of IMS subsystem interfaces and protocols: SIP, SDP, H.248, DIAMETER, TCP/UDP, TLS over TCP, IPSEC
- Experience integrating and working with distributed IP-based architectures: soft switches, gateways, SIP proxies, route engines, IP media servers, IP phones/IADs
- IMS interworking entities GUI configurations: P/I/S-CSCF, BGCF, MGCF, MRFC, MRFP, AGW, MGW, IBCF, TrGW
- Configuration knowledge of SBCs, NAT, firewall, authentication, encryption, and L2 switches
- Experience with WebRTC/WebSockets
- Working knowledge of Ericsson MTAS, MIO, WCG
- Knowledge of Ericsson IMS Application Servers (CAMEL/IS41) and EMS/NMS interfaces
- Experience with DHCP and DNS server configurations
- Familiarity with project/product QA life cycles, release/build management, defect management, and configuration control
- Debugging application layer logs: GUI logs, Java, SNMP, database logs
