protocol = function (protocolCode) {
  const lookup = { 1: 'icmp', 2: 'igmp', 6: 'tcp', 17: 'udp', 47: 'gre', 50: 'esp', 58: 'icmp6', 89: 'ospf', 103: 'pim', 132: 'sctp' };

  return lookup[protocolCode] || protocolCode;
}
Displays the protocol string instead of number code

@example
'{{ 1 | protocol }}'
this.$options.filters.protocol(1);

@param {int} protocolCode  The protocol code
@returns {string}          The human understandable protocol string