Danar Mahmood
Liverpool
Summary
Telecom core and IP network engineer with 10+ years of experience designing, deploying and automating high-availability, low-latency operator networks and 4G/5G core/IMS platforms. Proven leadership across core network, IP, NOC and systems teams; delivered multi-DC geo-redundant architectures, EPC/5GC builds, and cost-saving in-house tooling. Strong Linux/virtualisation background with Python automation and data-driven operations (monitoring, log analytics, dashboards).
Overview
14
14
years of professional experience
Work History
IT Manager
A-Z MiddleEast Food
Liverpool
05.2024 - Current
- Delivered internal business systems: B2B e-commerce site, in-house POS, and integrations for operations reporting.
- Built centralized data pipelines and Power BI dashboards to improve visibility into sales, inventory and performance.
5G Cellular Network Technologist
Digital Catapult
Belfast
09.2022 - 05.2024
- Designed and operated private 4G/5G testbeds (Industry 4.0 and enterprise environments) including network, virtualisation cluster and Kubernetes.
- Owned security posture of testbeds (firewalls, segmentation, hardening) and supported security improvements across additional UK testbeds.
- Worked with industry/academic partners and SMEs to translate needs into 4G/5G solution designs; produced documentation and masterclasses.
IP & Core Network Manager
NetSpot Solutions
09.2019 - 09.2022
- Led four functions: IP, Mobile Core, NOC and System Administration.
- Designed, installed and operated EPC core elements (SGW/PGW, MME, HSS, PCRF, AAA, TWAG/TWAP) and supported 5G NSA evolution.
- Designed and managed an IP/MPLS network (50+ routers, 200+ switches) reaching ~250 Gbps aggregate throughput (Whitebox Routers and Switches, + Cisco ASR9k/NCS).
- Architected geo-redundant multi-DC core/IMS environment: AMF/SMF/UPF, MME, SPGW, HSS/UDM, SBC, SMSC, IP-SM-GW, CGNAT and IMS nodes.
- Reduced cost and dependency on vendor support by independently designing/expanding 4G/5G clusters (incl. CUPS), and HSS clusters.
- Built internal tools for proactive operations: log collection/analysis and Power BI visualisations; improved time-to-diagnosis for rejections/drops.
- Owned vendor evaluation and procurement for networking equipment, servers, SIM systems and services; managed international SMS/voice connections.
- Achievement: Grew the network from ~14,000 to 640,000 4G-connected users through architecture redesign and backbone modernization (MPLS, OSPF/BGP, L2/L3VPN).
- Worked as Solution Architect to develop in-house solutions such as (OCS, PCRF, and DRA), which saved the company millions of dollars.
Network Engineer
Crescent Petroleum
Iraq
02.2019 - 09.2019
- Designed and supported enterprise WAN/LAN across multi-site operations; improved availability, routing efficiency and security monitoring.
System Administrator / EPC Engineer
Gorannet ISP
Iraq
09.2016 - 02.2019
- Administered Cisco routing/switching and firewalls; operated virtualisation estate (10 ESXi hosts, 120+ VMs).
- Supported EPC elements (HSS, MME, UGW) and voice systems (voice gateways, CUCM/UCCX/CMS, core/CUPS, CUC).
Network Engineer
NetPro
08.2014 - 03.2016
Network Instructor
06.2015 - 01.2017
Graphic Designer
06.2012 - 01.2017
Skills
- 4G EPC
- SAEGW
- SGW
- PGW
- MME
- HSS
- PCRF
- OCS
- DRA
- AAA
- 3GPP
- RADIUS
- Diameter
- TWAG
- TWAP
- 5G NSA
- 5GC
- AMF
- SMF
- UPF
- UDM
- UDR
- VoLTE
- IMS
- SBC
- P-CSCF
- S-CSCF
- ENUM
- SMSC
- IP-SM-GW
- Integrations
- BGP
- OSPF
- EIGRP
- MPLS
- VRF
- STP
- L2VPN
- L3VPN
- Backbone design
- Multi-DC routing
- Segmentation
- CGNAT
- Fortinet
- Palo Alto
- Cisco ASA
- Policy
- Edge protection
- Linux
- VMware ESXi
- Docker
- Kubernetes
- HAProxy
- Automation
- Python
- Bash
- Monitoring
- PRTG
- Log pipelines
- Dashboards
- Analytics
- Power BI
- Incident support
- Optimisation
Key Highlights
- Redesigning, Configuring and Managing a 4G network, and scaling it from ~14K to 640K connected users.
- Redesigning a primitive backbone, and implementing new technologies in the (MPLS, OSPF/BGP, L2/L3VPN).
- Designed and operated EPC and IMS domains (MME, HSS, SGW/PGW, PCRF, OCS, DRA; SBC, P-/S-CSCF, SMSC, IP-SM-GW; interconnects).
- Built geo-redundant multi-DC CUPS clusters for 4G/5G NSA (SPGW-CPF/UPF, MME pooling; additional UPFs in 3rd/4th DC).
- Worked as solution architect to develop an in-house OSS Solution (configuration, monitoring, software management) that avoided high vendor licensing/support costs.
- Worked as solution architect to develop in-house OCS, PCRF and DRA solutions.
- Worked as solution architect to develop VoLTE Capable softphone, which could handle SIM authentication.
- Hands-on delivery: Designed and deployed two full 4G networks end-to-end within one month (IP plan, ESXi Configuration, Network Configuration, security/CGNAT, Mobile core elements, EMS).
- Solutions consulting experience: requirements discovery with SMEs, designing 4G/5G solutions, documentation and enablement sessions.
Certifications Training
- CCNP Service Provider
- CCNP R&S
- CCNA Security
- CCDA
- PCNSA
- LPIC-1
- 5G Core Network Engineer
- Huawei HSS / UGW / MME Maintenance & Administration (lab training)
Selected Consulting Side Projects
2021-01-01, 2023-10-01, Redesigned ISP backbone and introduced MPLS + BGP/OSPF + L2/L3VPN; deployed three Fortinet CGNAT units., Designed an end-to-end DPI solution (solution architecture, integration approach, infrastructure)., Built an OSS platform to replace NetAct functions (configuration management, monitoring, software management) with major cost avoidance., Delivered two end-to-end 4G networks from scratch (planning, ESXi, security/CGNAT, EPC nodes, EMS, monitoring, SIM provisioning)., Deployed geo-redundant 4G/5G NSA CUPS clusters across multiple DCs (SPGW-CPF/UPF, MME pooling, additional UPFs) and integrated IMS/LICF/CBC/TWAG., Deployed and tuned HAProxy for authentication and API transformations; implemented geo-restriction bypass as required.
Personal Information
Title: Senior Mobile Core & IP Network Engineer
Timeline
IT Manager
A-Z MiddleEast Food
05.2024 - Current
5G Cellular Network Technologist
Digital Catapult
09.2022 - 05.2024
IP & Core Network Manager
NetSpot Solutions
09.2019 - 09.2022
Network Engineer
Crescent Petroleum
02.2019 - 09.2019
System Administrator / EPC Engineer
Gorannet ISP
09.2016 - 02.2019
Network Instructor
06.2015 - 01.2017
Network Engineer
NetPro
08.2014 - 03.2016
Graphic Designer
06.2012 - 01.2017