Split Shim-layer architecture and Integrated architecture

Create two sub-sections in "05 Detailed architecture" for the Shim-layer
architecture and the Integrated architecture.
Fix several implementations bugs and warnings. Remove numbering of
files.

JIRA: PROMISE-57

Change-Id: Ia0b4067c0cc3a461e54b6b010f8310764fb08d73
(cherry picked from commit 9fdb1e0b443e68f67b0978e27ec211bd7aa4cd89)

1 files changed, 36 insertions, 0 deletions

diff --git a/docs/requirements/intro.rst b/docs/requirements/intro.rst
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+============
+Introduction
+============
+
+Resource reservation is a basic function for the operation of a virtualized
+telecom network. In resource reservation, VIM reserves resources for a certain
+period as requested by the NFVO. A resource reservation will have a start time
+which could be into the future. Therefore, the reserved resources shall be
+available for the NFVO requested purpose (e.g. for a VNF) at the start time for
+the duration asked by NFVO. Resources include all three resource types in an
+NFVI i.e. compute, storage and network.
+
+Besides, NFVO requires abstracted NFVI resource capacity information in order
+to take decisions on VNF placement and other operations related to the virtual
+resources. VIM is required to inform the NFVO of NFVI resource state
+information for this purpose. Promise project aims at delivering the detailed
+requirements on these two features defined in ETSI NFV MAN GS [NFVMAN]_,
+the list of gaps in upstream projects, potential implementation architecture
+and plan, and the VIM northbound interface specification for resource
+reservation and capacity management.
+
+Problem description
+===================
+
+OpenStack, a prominent candidate for the VIM, cannot reserve resources for
+future use. OpenStack requires immediate instantiation of Virtual Machines
+(VMs) in order to occupy resources intended to be reserved. Blazar can reserve
+compute resources for future by keeping the VMs in shelved mode. However, such
+reserved resources can also be used for scaling out rather than new VM
+instantiation. Blazar does not support network and storage resource reservation
+yet.
+
+Besides, OpenStack does not provide a northbound interface through which it can
+notify an upper layer management entity e.g. NFVO about capacity changes in its
+NFVI, periodically or in an event driven way. Capacity management is a feature
+defined in ETSI NFV MAN GS [NFVMAN]_ and is required in network operation.