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IP Transmission/Transport Designer (12 month FTC)

Date: 15-May-2021

Location: SLOUGH, GB

Company: Telefonica S.A.

Here at O2, we’re about technology that creates exciting experiences. It’s why there are over 25 million people who choose to live life on O2. 


Being part of Telefonica, one of the world’s most creative digital companies, we’re able to open up all sorts of possibilities – not just for customers, but for the people who work for us, too. 


Great benefits. Great rewards. High-quality training. Ongoing career development. Flexible working. These are just some of the reasons we attract great talent. 


Our inclusive approach to recruitment helps us be a true reflection of our customers and their communities. That’s why everybody’s welcome at O2 – it’s time to get everyone in the room. 



About the Team:


Transmission Engineering are part of Telefónica UK Networks, and are responsible for the architecture, evolution, design and infrastructure capacity of our mobile core and access transmission IP networks.


From our high capacity dark fibre core, to our IP Ethernet backhaul network, we deliver innovative and class leading solutions utilising some of the latest and most exciting transmission and transport technologies.


Telefonica UK co-operates with a number of providers of Optical, Ethernet and IP connectivity products. Using these products as the underlying technologies, the Transmission Engineering team builds IP connectivity solutions between Core RAN equipment as RNCs, BSCs and Security Gateways to Cell Site Equipment, as BTSs, NodeBs and eNodeBs.


Your Role:


Working with Architects and other designers within the Transmission Engineering team, the role holder will engage in IP design activities within the Core and Backhaul Transport Networks. IP Design activities typically using Ethernet / microwave/DWDM underlying technologies and consider both technical and commercial parameters.




Role responsibilities include developing, documenting and maintaining IP networking designs that make use of different connectivity products. The role holder shall consider product specifications as for example physical availability, capacity and delay, and deliver commercial evaluations, testing, integration and operation.


Solutions must be aligned with business requirements and technology standards that include network simplification, increasing capacity, resilience, disaster recovery, network management and security.


The person holding this role will develop and analyse performance reports of Telefonica UK’s Transmission Network. These analysis will be presented to members within and outside the team.


The role requires business and commercial skills in addition to high levels of technical expertise. From time to time it will be necessary to produce RFx documentation for transmission network solutions and to evaluate supplier responses.

Responsibilities also include to act as the Technical Lead for the projects assigned and work in co-operation with the Project Manager to identify the involved parties and resources required for each project.


The role holder is expected to keep abreast of applicable technology developments and understand how they may be applicable to Telefónica UK.         


Skills & experience:


  • Deep theoretical and practical knowledge of TCP, UDP and the main L3/L2 routing protocols.
  • Experienced in designing, planning, configuring and testing of IP/MPLS transport networks.
  • Experience in developing and analysing comprehensive network performance reports.
  • Clear understanding of IP Quality of Service and the mechanisms used to prioritize traffic at Ethernet and IP layers.
  • Expertise in producing carrier class IP connectivity solutions, using one or more of: IP / Ethernet / microwave / satellite / WDM as the underlying media.
  • Direct experience in creating High Level and Low Level Designs and Scopes of Work applied to IP Networks.


Additional Information:


Applicants will also ideally be degree level qualified, with significant experience with working in a telecommunications technical design or architecture role obtained from working within a network operator or equipment vendor.


Candidates should possess a flexible and logical approach with demonstrable skills in solving complex technical problems. They also need to be results oriented with outstanding self-reliance, resourcefulness and initiative coupled with an ability to communicate complex concepts simply and effectively across different teams.


Desirable criteria:


  • Network protocols (Layer 2: ARP, Ethernet, PPP; Layer 3 IP, Layer 4 TCP, UDP; Layer 6 SSH Layer 7 HTTP/HTTPS, DHCP)
  • Transmission and IP transport performance (Ethernet OAM); Performance counters/KPIs, (delay, packet loss, jitter), Service LSA, QoS
  • Statistics knowledge (bias, variance, mean, median, percentiles), data distribution (deal with null values,  exceptional/extreme values, data aggregation, time series related), know data visualization (Tableau) is a plus
  • SQL: be able to pull data from multiple tables in database (via merge, filter, groupby etc); Skilled in excel, (such as pivot-table, vlookup, plot diagrams); know any coding language, (such as python) is a plus and will be very useful for the role. Familiarity with transport design in mobile networks would be highly advantageous.
  • Experience in producing HLDs and LLDs for Transport IP Network elements preferably related to ALU 7750 environments.
  • Experience in transport designs making use of Juniper platforms and specifically MX and PTX series routers and EX4300 used as Satellites, implementation of advanced QoS and Policy Routing in JunOS, JunOS Space EMS, and Juniper Northstar.
  • Knowledge of implementation of VPLS bridging and eVPN.
  • Good understanding of Virtualization concepts.
  • Experience in designing backhaul solutions for mobile access is desirable.


The role is mainly office based in Slough (flexible) but travel to other parts of the UK or to other countries (e.g. other Telefónica operating businesses) may be required from time to time.




We’ll be sending you emails about the status of your application. To make sure you receive these, please add and to your Safe Senders list.


We’re looking to pay a great compensation package (depending on experience) for this position. We also offer plenty of extras to sweeten the deal, which could include things like bonuses, life assurance cover, health care and lots of flexible benefits.  


Also, every employee has their personal development supported with a LinkedIn learning account; plus other role specific learning available through our award-winning digital learning platform - O2 Campus. 


We also believe a great work-life balance is important, so we’re open to considering flexible working arrangements. Like to know more, feel free to raise it.  


Join us and we’ll encourage you to be bold every day. So take a deep breath, your career is about to go to exciting new places. 


If you have any questions around the role then please email who will be happy to help.