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Security & Network Designer

Date: 19-Sep-2022

Location: SLOUGH, GB

Company: Telefonica S.A.

It matters to us that Team O2 is as diverse as the communities we serve. 

We’re aware that we need more diversity in our senior leadership roles, so we welcome and encourage people from all backgrounds to apply. 

Whoever you are, O2 has a place for you. 

Come join us.


Job grade: PCGU/VM Level 5

Location(s):  Slough


About the role


The purpose of this role is to provide security consultancy services to business units within Telefónica UK, to deliver high and detailed level network security designs and to build new security infrastructures to assist Telefónica UK with the delivery of new functionality and service improvements. Furthermore, the holder of this role inputs into strategic decisions, planning ahead for the future.


The holder of this role will have TDA responsibilities for some elements of the security infrastructure and be responsible for supervising performance data and implementing improvement programs should performance drop below target values for these systems.

This role also provides a critical issue function for Operations to assist with the resolution of complex problems and address any inherent design issues.


This role requires experienced knowledge in a wide range of information security domains with a focus on network security technologies such as firewalls, intrusion prevention and remote access.


Key Responsibilities



  • Provide security design, guidance, and technical approval for new projects across the business and ensure they carry out to Telefónica (UK) Corporate Security policies.
  • Ensure Security Operational Acceptance criteria are met for all new projects and any gaps are highlighted to the business.
  • Design and implementation of security infrastructure in line with the security architecture / framework
  • Perform upgrades and install hot fixes to the systems mentioned above.
  • Ensure documentation of all security infrastructures are relevant and up to date.
  • Present security changes on the daily change board and CAB.
  • Approve Authority for Network Connection (ANC) requests.
  • Assist with the resolution of security issues and act as an escalation point for our internal 3rd line operational support teams enabling faster fix and reducing total cost of failure.


What We Need from You:


Must possess specialist knowledge and in-depth hands-on experience of working with security technologies such as firewalls, intrusion detection / prevention, SIEM and vulnerability management tools. Experience with the following technologies is important:


  • Checkpoint/Fortinet/Cisco FW/Juniper
  • SecureID
  • Radius
  • TippingPoint
  • Tripwire


What's in it for you?


As you're already a valued member of the Virgin Media or O2 family, you'll know lots about the amazing stuff we do to take care of our people. As we're prioritising our amazing internal talent, this role is only eligible for internal applicants or applications from our contingent workforce. We can chat to you one on one about how your overall benefits may change, if you’re successful.


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.