Figure 4-19 Intra-application versus inter-application communication With this approach, when it comes to inter-application communication within each application  boundary we can still benefit from the key capabilities of a service mesh: For inter-application communication, services that will be exposed outside of the mesh – via  the mesh ingress and egress gateways – and guarded by an API gateway. This approach  enforces the application boundary, of which the mesh itself has no notion.  An API gateway also comes with additional benefits to the application: Additionally, if the API gateways are part of an API management solution, that solution can  control how the application makes itself available to other applications within the mesh,  outside of the mesh, and even beyond the enterprise. It allows consumers to explore the APIs  available via a developer portal, and to subscribe to an appropriate plan of use for the APIs  they want to use. Then, at run time, it enables the application owners to recognize, control  and perhaps even bill differing types of consumers of the APIs. It ensures that all consumers  Chapter 4. Cloud-native concepts and technology  125 GLYPH<SM590000> Service discovery GLYPH<SM590000> Traffic management GLYPH<SM590000> Traffic encryption  GLYPH<SM590000> Observability and traceability  GLYPH<SM590000> Authentication and authorization  GLYPH<SM590000> Failure recovery GLYPH<SM590000> Gateway load balancing  GLYPH<SM590000> Gateway throttling GLYPH<SM590000> Service mesh entry point security (for example generating tokens) GLYPH<SM590000> Policy enforcement GLYPH<SM590000> Abstraction from internal communication protocols   6 H U Y L F H  6 H U Y L F H  6 H U Y L F H $ 3 , * D W H Z D \  6 H U Y L F H  6 H U Y L F H  6 H U Y L F H  6 H U Y L F H  6 H U Y L F H  6 H U Y L F H , Q W H U D S S O L F D W L R Q F R P P X Q L F D W L R Q , Q W U D D S S O L F D W L R Q F R P P X Q L F D W L R Q $ 3 , * D W H Z D \ $ 3 , J D W H Z D \ $ S S O L F D W L R Q E R X Q G D U \  6 H U Y L F H 0 L F U R V H U Y L F H F R P S R Q H Q W , Q W H U D S S O L F D W L R Q $ 3 , , Q W U D D S S O L F D W L R Q $ 3 , 6 H U Y L F H P H V K F R P P X Q L F D W L R Q