I have worked with, developed and tested many kinds of network and networking equipment including: LAN, WAN, Radio (conventional, MPT1327, Tetra), fixed telecoms, wireless public telecoms (GSM, GPRS, UNTS)
IP networks and Ethernet
My IP networking experience has covered:
- Video and Voice over IP - VoIP. This has included analysis down to timing and timestamps of RTP packets
- Mulicast, including IGMP protocol and layer 3 routing
- NTP and SNTP, investigating issue and presenting on their differences
- Designing and configuring networks with VLANs, link aggregation and layer 3 routing
Public mobile & fixed telecoms networks
GSM, GPRS, UMTS, SS7
Tetra mobile radio networks
My Tetra work covered analysis and testing of the Tetra protocol between terminals and basestations. This included participation in interoperability trials and demonstrations with other major Tetra vendors.
My testing of Tetra infrastructure extended to other transport protocols within the core network including: voice over frame relay; IP, QSIG, Q931, ftp, Motorola Smartzone protocols
MPT1327 and conventional mobile radio
I developed and maintained firmware in assembler and C for multiple handsets that operated using the MPT1327 and MPT1343 radio protocols
I developed and customised firmware for multiple conventional handsets that used "Select 5" tone signalling and "PL" sub-audio signalling.