IMS Consultant
Vodafone Hungary
(Telecommunications, 5000-10.000 employees)
Keywords
GPRS Core Networks
Testing
Billing
Message Transfer Agent
Medical Emergency
Network Engineering
Cisco
Voice over Broadband (VoBB)
Swap (finance)
Skills
I have in-depth experience with several types of delivery projects both in the EPC and IMS domains. Projects include newly deployed networks, merging of existing networks, vendor swaps and major migrations between networks.
I have extensive experience designing, planning, testing and implementing, among others, on the following network elements:
MME, S-GW, P-GW, SGSN, GGSN, A-SBC/P-CSCF, I-SBC, E-CSCF, S/I-CSCF, MTAS, ATS, DRA, PCRF with the following vendors: Huawei, Ericsson, Cisco/Starent.
I have experience in integrating, testing and troubleshooting LI solutions with the above network elements.
I am very dedicated to my work and enjoy planning and executing large-scale projects, coordinating and cooperating with a variety of participants and stakeholders from management through to peer departments such as IT/provisioning, billing/mediation/charging, Lawful Interception and Data Disclosure, etc.
Major projects:
2019-2023 Vodafone Hungary
- VoLTE Network redesign to accomodate fixed line, VoBB subscribers and create a converged IMS Core network
- Introduction of VoWifi, SMSoIP/IP-SM-GW, VoLTE & VoWifi Emergency and VoLTE Outbound Roaming services in parallel
2017-2019 Digi Hungary
- Plan, deploy, test and launch a completely new VoLTE + 2G network including EPC, IMS and SMSC/IP-SM-GW
2016 Telenor Hungary
- VoLTE service introduction
2014-2016 Vodafone Hungary
- LTE introduction, LTE Roaming planning, testing and launch
2012-2013 Vodafone Netherlands
- Massive APN migration project. Migration of over 500 APNs within 6 months
2008-2010 Telekom Hungary
- Packet Core network swap from Ericsson to Huawei
I have extensive experience designing, planning, testing and implementing, among others, on the following network elements:
MME, S-GW, P-GW, SGSN, GGSN, A-SBC/P-CSCF, I-SBC, E-CSCF, S/I-CSCF, MTAS, ATS, DRA, PCRF with the following vendors: Huawei, Ericsson, Cisco/Starent.
I have experience in integrating, testing and troubleshooting LI solutions with the above network elements.
I am very dedicated to my work and enjoy planning and executing large-scale projects, coordinating and cooperating with a variety of participants and stakeholders from management through to peer departments such as IT/provisioning, billing/mediation/charging, Lawful Interception and Data Disclosure, etc.
Major projects:
2019-2023 Vodafone Hungary
- VoLTE Network redesign to accomodate fixed line, VoBB subscribers and create a converged IMS Core network
- Introduction of VoWifi, SMSoIP/IP-SM-GW, VoLTE & VoWifi Emergency and VoLTE Outbound Roaming services in parallel
2017-2019 Digi Hungary
- Plan, deploy, test and launch a completely new VoLTE + 2G network including EPC, IMS and SMSC/IP-SM-GW
2016 Telenor Hungary
- VoLTE service introduction
2014-2016 Vodafone Hungary
- LTE introduction, LTE Roaming planning, testing and launch
2012-2013 Vodafone Netherlands
- Massive APN migration project. Migration of over 500 APNs within 6 months
2008-2010 Telekom Hungary
- Packet Core network swap from Ericsson to Huawei
Project history
12/2019
-
06/2023
- Responsible for the service design, implementation and testing/validation of the major merger project after Vodafone purchased Liberty Global’s fixed line services in Czech Republic, Germany, Hungary and Romania.
- The project scope was to expand Vodafone’s VMWare-based virtualized VoLTE IMS to allow fixed line (VoBB) services in the new FMC IMS network.
- Work closely with Huawei engineers on the design and implementation of the expanded service without interruption to existing live VoLTE services.
- Participate in in-depth troubleshooting of VoLTE-related issues in the existing network.
- Act as technical SPOC regarding IMS services towards peer departments such as Provisioning, Charging/Mediation, IP teams for network connectivity.
- Re-design existing VoLTE Lawful Interception solution based on Huawei recommendations to allow LI for newly migrated VoBB subscribers.
- Oversee and participate in migration of 700,000+ fixed line subscribers from Liberty Global’s network to the expanded and newly deployed IMS NEs in 15 iterations.
- Oversee and organize complex upgrade project to bring all IMS elements to the latest available release followed by VMWare upgrade to the latest bundle.
- Oversee and coordinate the service design and HLD provided by Huawei for VoWifi, SMSoIP, VoLTE&VoWifi Emergency calls and VoLTE Outbound Roaming in parallel
- Plan the above 4 services with special consideration of the effects and interaction between each other and the effects on existing VoLTE services.
- Design, Configure and Implement the 4 services first in test and then in live environment with minimal support from the vendor both in the IMS and EPC domains.
- Give technical input in preparation for OneNumber introduction projects.
01/2017
-
12/2019
Senior Core Network Engineer
Digi Hungary
(Telecommunications, 500-1000 employees)
* Senior Core Network Engineer leading a team of 5 engineers responsible
for IMS
* Set up a completely new mobile core network originally designed as
VoLTE/VoWifi only. Later ICS-based (IMS Centralized Services) 2G
network was added to allow all older mobiles to access the network. (Digi is
the 4th mobile operator in Hungary launching commercial service at the end
of May 2019)
* Responsible for Digi side of dimensioning, planning, designing,
implementing newly deployed Ericsson virtualized IMS network on Ericsson
BSP platform with Openstack-based CEE virtualization environment.
* Configure and troubleshoot VoLTE / VoWifi / CAMEL-based ICS (for 2G
and roaming) network starting from Ericsson basic configuration and finetuning
it according to local network, interconnect partner and VoLTE/VoWifi
terminal requirements.
* Troubleshoot and tune network to allow interworking with SIP-based UEs
from many different vendors including Samsung, Huawei, LG, OnePlus,
Xiaomi, Allview, etc. (UE vendor side cooperation not always available thus
problems have to be solved on mobile network side.)
* Main nodes in IMS network in Digi: SBC (SBG + BGF) / P-CSCF and IBCF,
CSCF (I/S/E-CSCF), MTAS (MMTel AS, SCCAS, MRFC, gsmSCF,
Interworking AS), DNS/ENUM, AAA, MRFP, MGCF)
* Carry out and troubleshoot upgrades of Ericsson CEE virtualization
environment based on Openstack using Ericsson scripts and guides.
* Plan and re-arrange virtualized nodes to make space for testing VNFs for
converged fixed network IMS in proof-of-concept phase.
* Plan and implement network configuration for emulating existing fixed
network services in the virtualized IMS environment in preparation for fixed
core network swap.
* In-depth troubleshooting of IMS call-flows using pcap capture files with
complex Wireshark filters and IMS nodes' internal logs and
application/system level debug tracing.
* Design interconnect configuration for SIP and ISUP connection with
partners.
* Lead integration and troubleshooting of LI related equipment and functions
for compliance with regulatory requirements.
* Lead and train team of engineers with approved access to LI equipment for
day-to-day operations
* Guide team of 2 focusing on VoLTE/VoWifi terminal testing to get mobile
phone software approved by Digi (vendors such as Samsung, Huawei, LG,
etc)
* Participate in EPC network troubleshooting when necessary
for IMS
* Set up a completely new mobile core network originally designed as
VoLTE/VoWifi only. Later ICS-based (IMS Centralized Services) 2G
network was added to allow all older mobiles to access the network. (Digi is
the 4th mobile operator in Hungary launching commercial service at the end
of May 2019)
* Responsible for Digi side of dimensioning, planning, designing,
implementing newly deployed Ericsson virtualized IMS network on Ericsson
BSP platform with Openstack-based CEE virtualization environment.
* Configure and troubleshoot VoLTE / VoWifi / CAMEL-based ICS (for 2G
and roaming) network starting from Ericsson basic configuration and finetuning
it according to local network, interconnect partner and VoLTE/VoWifi
terminal requirements.
* Troubleshoot and tune network to allow interworking with SIP-based UEs
from many different vendors including Samsung, Huawei, LG, OnePlus,
Xiaomi, Allview, etc. (UE vendor side cooperation not always available thus
problems have to be solved on mobile network side.)
* Main nodes in IMS network in Digi: SBC (SBG + BGF) / P-CSCF and IBCF,
CSCF (I/S/E-CSCF), MTAS (MMTel AS, SCCAS, MRFC, gsmSCF,
Interworking AS), DNS/ENUM, AAA, MRFP, MGCF)
* Carry out and troubleshoot upgrades of Ericsson CEE virtualization
environment based on Openstack using Ericsson scripts and guides.
* Plan and re-arrange virtualized nodes to make space for testing VNFs for
converged fixed network IMS in proof-of-concept phase.
* Plan and implement network configuration for emulating existing fixed
network services in the virtualized IMS environment in preparation for fixed
core network swap.
* In-depth troubleshooting of IMS call-flows using pcap capture files with
complex Wireshark filters and IMS nodes' internal logs and
application/system level debug tracing.
* Design interconnect configuration for SIP and ISUP connection with
partners.
* Lead integration and troubleshooting of LI related equipment and functions
for compliance with regulatory requirements.
* Lead and train team of engineers with approved access to LI equipment for
day-to-day operations
* Guide team of 2 focusing on VoLTE/VoWifi terminal testing to get mobile
phone software approved by Digi (vendors such as Samsung, Huawei, LG,
etc)
* Participate in EPC network troubleshooting when necessary
04/2016
-
12/2016
Senior Core Network Engineer
Huawei Technologies Hungary
(Telecommunications, >10.000 employees)
* Support Telenor virtualized IMS project for VoLTE introduction
* Participate in live network deployment of virtualized IMS network elements
on Huawei E9000 NFV platform
* Vertical integration of FusionSphere Openstack, FusionManager, MANO
and Virtualized Network Functions
* Complex troubleshooting of IMS network elements during setup of test
environment
* Responsible for complete Acceptance Testing of all services and functions
in the test and live networks.
* Live network integration of IMS network elements with all peer devices.
* Participate in live network deployment of virtualized IMS network elements
on Huawei E9000 NFV platform
* Vertical integration of FusionSphere Openstack, FusionManager, MANO
and Virtualized Network Functions
* Complex troubleshooting of IMS network elements during setup of test
environment
* Responsible for complete Acceptance Testing of all services and functions
in the test and live networks.
* Live network integration of IMS network elements with all peer devices.
05/2014
-
03/2016
PS/EPC Core Network Contractor
Manpower Group for Vodafone Hungary
(Telecommunications, 50-250 employees)
* Support PS Core Network team with Cisco ASR5K SGSN/GGSN/MME/S-
GW/P-GW
* Statistical counter replanning/update following software upgrade on
SGSN/MME/GGSN/S-GW/P-GW platforms
* Responsible for Cisco GGSN/S-GW/P-GW release upgrades
* Responsible for enabling LTE for all corporate APNs
* Test new network configuration/features before live network introduction
* Create SGSN/GGSN scripts for configuration optimization and Enhanced
Charging Service new service implementation received from
Business/Marketing departments
* GGSN/P-GW SPI and DPI development, testing and configuration for new
business requirements
* GGSN/P-GW SPI and DPI re-planning to avoid fraudulent exploitation of
free traffic (avoiding DNS tunneling, HTTP proxy fraud, etc.)
* Continuous troubleshooting of problems experienced after LTE introduction.
* Responsible for technical aspect of complete LTE roaming (outbound and
inbound) introduction including feasibility analysis, technical preparation,
testing in test environment, live network preparation, testing and launch.
Continuous troubleshooting with Vodafone Roaming Services in case of
any issues with new roaming partner testing.
* Technical review of different vendors' DRA solutions for management
* Support operations teams during disaster recovery
* Continuous development and troubleshooting with local E2E Performance
Team to improve network performance
GW/P-GW
* Statistical counter replanning/update following software upgrade on
SGSN/MME/GGSN/S-GW/P-GW platforms
* Responsible for Cisco GGSN/S-GW/P-GW release upgrades
* Responsible for enabling LTE for all corporate APNs
* Test new network configuration/features before live network introduction
* Create SGSN/GGSN scripts for configuration optimization and Enhanced
Charging Service new service implementation received from
Business/Marketing departments
* GGSN/P-GW SPI and DPI development, testing and configuration for new
business requirements
* GGSN/P-GW SPI and DPI re-planning to avoid fraudulent exploitation of
free traffic (avoiding DNS tunneling, HTTP proxy fraud, etc.)
* Continuous troubleshooting of problems experienced after LTE introduction.
* Responsible for technical aspect of complete LTE roaming (outbound and
inbound) introduction including feasibility analysis, technical preparation,
testing in test environment, live network preparation, testing and launch.
Continuous troubleshooting with Vodafone Roaming Services in case of
any issues with new roaming partner testing.
* Technical review of different vendors' DRA solutions for management
* Support operations teams during disaster recovery
* Continuous development and troubleshooting with local E2E Performance
Team to improve network performance
05/2013
-
12/2013
Packet Core Network Integration Expert
Magyar Telekom (T-Mobile)
(Telecommunications, >10.000 employees)
* Cisco GGSN/P-GW regression testing for new software builds
* Cisco GGSN/P-GW acceptance testing prior to Mass Market APN migration
* New APN setup, integration and testing for various different projects based
on design documentation
* Corporate APN migration project
* Corporate APN configuration, integration and troubleshooting in a test
environment for all different models available at Magyar Telekom.
* Thorough testing and documentation of all functionalities involved in each
corporate APN type
* Pilot preparation and execution for each different type of APN
* Prepare and handover configuration templates to Operations Team for
corporate APN migration rollout
* Configuration and testing of Cisco enhanced charging service (DPI)
functionality based on design documentation.
* Troubleshoot various problems in the mobile packet core network
* Cisco GGSN/P-GW acceptance testing prior to Mass Market APN migration
* New APN setup, integration and testing for various different projects based
on design documentation
* Corporate APN migration project
* Corporate APN configuration, integration and troubleshooting in a test
environment for all different models available at Magyar Telekom.
* Thorough testing and documentation of all functionalities involved in each
corporate APN type
* Pilot preparation and execution for each different type of APN
* Prepare and handover configuration templates to Operations Team for
corporate APN migration rollout
* Configuration and testing of Cisco enhanced charging service (DPI)
functionality based on design documentation.
* Troubleshoot various problems in the mobile packet core network
10/2012
-
09/2013
Technical Lead for Vodafone Netherlands APN migration project
Flint Consulting for Cisco Systems
(Telecommunications, 50-250 employees)
* Responsible for technical aspect of Vodafone's corporate customer APN
migration between Cisco GGSNs.
* Consult with Cisco experts on APN reconfiguration strategy with special
consideration taken for bespoke APNs.
* Re-engineer APN configuration for 700+ corporate customer "legs" based
on the following assumptions:
* Configuration can be collected from the old GGSN and Edge-Routers
* Routing changes from VLAN to MPLS BGP
* Software version changes from Cisco ASR5K R9 to R12.2
* Both single-homed and multi-homed APNs involved
* Work in close contact with Vodafone and Ericsson/ENN for preparing large
number of special APN re-designs.
* Coordinate with Vodafone Group members in migrating APNs with complex
network architecture
* Create "Workorders" in Ericsson's system according to the agreements
between Vodafone, Ericsson and Cisco.
* Update existing network diagrams based on the new topology. Make these
available to Vodafone support team prior to migrations.
* Prepare, execute and finish APN migrations between 2 GGSNs including
pre- and post-checks.
* Reconfigure necessary parameters on IPBB routers to accommodate for
changing routing method.
* Execute migrations during Vodafone's service window (Monday 00:00-
06:00 and Wednesday 00:00-06:00)
* Output reports to Vodafone with Key Performance Indicators showing
migrations are successful.
migration between Cisco GGSNs.
* Consult with Cisco experts on APN reconfiguration strategy with special
consideration taken for bespoke APNs.
* Re-engineer APN configuration for 700+ corporate customer "legs" based
on the following assumptions:
* Configuration can be collected from the old GGSN and Edge-Routers
* Routing changes from VLAN to MPLS BGP
* Software version changes from Cisco ASR5K R9 to R12.2
* Both single-homed and multi-homed APNs involved
* Work in close contact with Vodafone and Ericsson/ENN for preparing large
number of special APN re-designs.
* Coordinate with Vodafone Group members in migrating APNs with complex
network architecture
* Create "Workorders" in Ericsson's system according to the agreements
between Vodafone, Ericsson and Cisco.
* Update existing network diagrams based on the new topology. Make these
available to Vodafone support team prior to migrations.
* Prepare, execute and finish APN migrations between 2 GGSNs including
pre- and post-checks.
* Reconfigure necessary parameters on IPBB routers to accommodate for
changing routing method.
* Execute migrations during Vodafone's service window (Monday 00:00-
06:00 and Wednesday 00:00-06:00)
* Output reports to Vodafone with Key Performance Indicators showing
migrations are successful.
11/2008
-
08/2012
Core Network Technical Support Engineer / Lead engineer for mobile PS Core network products
Huawei Technologies Hungary
(Telecommunications, >10.000 employees)
* Oversee hardware installation by sub-contractor of newly delivered Huawei
SGSNs and GGSNs.
* Installation, integration and commissioning of Huawei SGSNs and GGSNs.
* Integration of SGSN and GGSN with all peer nodes such as HLR/AuC, EIR,
RNC (Iu over ATM and IP), BSC (Gb over FR and IP), AAA, PCRF, OCS,
LIG, CG, MSS (as STP). Configuration of all interfaces for these nodes. Indepth
troubleshooting during interconnection configuration.
* Complete system and site acceptance testing for all functions, features and
interfaces of Huawei SGSN delivered to T-Mobile Hungary together with T-
Mobile staff (approx. 280 test cases).
* Write script for the migration of RNCs/BSCs from old equipment to Huawei.
* Configuration implementation and supervision of SGSN status during
nighttime cutovers of RNCs and BSCs from legacy Nortel PS Core network
to new Huawei equipment during the entire migration process.
* Supervision of GGSN status during APN cutovers from Nortel PS Core
network for the entire migration process. (4 Mass Market and over 250
corporate APNs)
* Network performance analysis of PS Core equipment during migration.
* First/second line support during and after migration. 24/7 on-call duties for
Huawei PS equipment in T-Mobile Hungary network.
* Troubleshooting technical issues during system acceptance and during live
network operation. Close communication with Chinese R&D about root
cause analysis and solution of problems. Collect information for
troubleshooting and contact customer when further testing/collection is
necessary. Communicate status, progress and results towards the
customer.
* Consult with customer technical staff and Chinese R&D about new feature
implementation possibilities and methods.
* Track and implement all live network related tasks such as software
patches, upgrades, hardware replacement/expansion, new feature
introduction, routine equipment health check. Communicate the details with
the customer for all of the above network activities.
SGSNs and GGSNs.
* Installation, integration and commissioning of Huawei SGSNs and GGSNs.
* Integration of SGSN and GGSN with all peer nodes such as HLR/AuC, EIR,
RNC (Iu over ATM and IP), BSC (Gb over FR and IP), AAA, PCRF, OCS,
LIG, CG, MSS (as STP). Configuration of all interfaces for these nodes. Indepth
troubleshooting during interconnection configuration.
* Complete system and site acceptance testing for all functions, features and
interfaces of Huawei SGSN delivered to T-Mobile Hungary together with T-
Mobile staff (approx. 280 test cases).
* Write script for the migration of RNCs/BSCs from old equipment to Huawei.
* Configuration implementation and supervision of SGSN status during
nighttime cutovers of RNCs and BSCs from legacy Nortel PS Core network
to new Huawei equipment during the entire migration process.
* Supervision of GGSN status during APN cutovers from Nortel PS Core
network for the entire migration process. (4 Mass Market and over 250
corporate APNs)
* Network performance analysis of PS Core equipment during migration.
* First/second line support during and after migration. 24/7 on-call duties for
Huawei PS equipment in T-Mobile Hungary network.
* Troubleshooting technical issues during system acceptance and during live
network operation. Close communication with Chinese R&D about root
cause analysis and solution of problems. Collect information for
troubleshooting and contact customer when further testing/collection is
necessary. Communicate status, progress and results towards the
customer.
* Consult with customer technical staff and Chinese R&D about new feature
implementation possibilities and methods.
* Track and implement all live network related tasks such as software
patches, upgrades, hardware replacement/expansion, new feature
introduction, routine equipment health check. Communicate the details with
the customer for all of the above network activities.
Local Availability
Only available for remote work
