One document matched: draft-hares-vnf-pool-use-case-01.xml
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<rfc category="info" docName="draft-hares-vnf-pool-use-case-01" ipr="trust200902">
<front>
<title abbrev="vnf-pool-use-case">Use Cases for Resource Pools with Virtual Network Functions (VNFs) </title>
<author fullname="Susan Hares" initials="S" surname="Hares">
<organization>Hickory Hill Consulting</organization>
<address>
<postal>
<street>7453 Hickory Hill</street>
<!-- Reorder these if your country does things differently -->
<city>Saline</city>
<region>CA</region>
<code>48176</code>
<country>USA</country>
</postal>
<email>shares@ndzh.com</email>
<!-- uri and facsimile elements may also be added -->
</address>
</author>
<date month="February" year="2014"/>
<area>INT</area>
<workgroup>VNF BOF</workgroup>
<abstract>
<t> In the context of virtualization, a service essentially consists of a set of
Virtualized Network Functions (VNFs) with each VNF building on top of virtualization
infrastructure to implement a specific network functions along with the data connections between VNFs.
VNFs may be highly distributed existing in devices in data center networks,
mobile networks or satellite networks. In some of these environments, the resources are highly constrained.</t>
<t> This draft provides seven use cases the author has observed in demonstrations or deployments
for the following network function virtualization: cloud bursting, parental controls,
load balancer for multipath (L1-L7), WAN optimization that runs either between access nodes
and Data Centers, WAN optimization between mobile phones and Data Centers (through access nodes),
application placement optimization, and optimized placement of web applications utilizing minimal data transfer.
</t>
</abstract>
</front>
<middle>
<section anchor="INTRO" title="Introduction" toc="default">
<t> </t>
<t> Certain network services within access networks, data center networks, and WAN networks
are being virtualized. The service virtualization has been considered as part of the network function
virtualization (NFV) or the Software Defined Networking (SDN) technology
development. This draft focuses on the implementation of these network services
using units of virtual network function (VNF) denoted as a VNF set
where the each VNF is implemented as a pool of VNF instances.
Each VNF builds its VNF instances on top of virtualized infrastructure
to implement a specific network function (NF)connected to other network functions (NFs).
</t>
<t> For example, a VNF Firewall will have a pool of virtual firewall instances.
When VNF instances are highly distributed, such as in a DC network or some access edge nodes for IP RAN -
virtual function instances are built on a resource constraint environment where resource contention,
hardware status change, hardware or software failures may occur.
</t>
<t> </t>
<t> This introduction introduces the terms, lists deployed VNF use
cases documented in this draft, and summarizes the problems that Virtual Network Function Pools have.
</t>
<section title="Terms">
<t> </t>
<t> The VNF Problem statement <xref
target="I-D.zong-vnfpool-problem-statement"/>
defines the terms reliability, VNF, VNF Pool, VNF Pool Element, VNF Pool User, VNF Pool
Manager, and VNF Set. This draft uses these definitions. The following definitions are
not defined within the VNF problem statement: Cloud Bursting, stateful parental controls,
WAN optimization, and application placement. These terms are defined below. </t>
<t> Cloud Bursting: the ability for Virtual processing to burst through the limits
of one virtual environment and automatically transfers a portion of the processing to
another virtual environment.
</t>
<t> Stateful parental controls: the ability for network access devices to have content
filters that react to traffic, location, and user. These controls follow the
user across multiple access points within a home network, or in a carrier network.
</t>
<t>WAN optimization: the ability to optimize traffic across a Wide-Area network.
WAN optimization often makes use of TCP FLOW optimizations (with IETF TCP features)
and TCP de-duplication of packets,
</t>
<t> Application placement: ability for coordinating software to place applications
based a combination of compute resources, data storage, network service, and
security concerns. Application placement may involve movement of some application
data, movement of some applications (data and compute), and movement of network
resources to service the applications. One type of network resource movement
is the movement of virtual network functions (VNFs) which are defined, created,
allocated with resources in a way to provide an integral unit to the application
placement control software.
</t>
<t> OTT (Over the Top): This industry terms implies an overlay network that
is overlaid on existing networks as a virtual network. </t>
<t> </t>
</section>
<section title="Use Case List">
<t> The use cases described in this draft are: </t>
<t><list style="symbols">
<t> Cloud Bursting </t>
<t> stateful parental controls implemented in access nodes and firewalls (stateful and regular) </t>
<t> load balancer doing multipath (supports L1-L7 optimization), </t>
<t> WAN optimization between access nodes and Data Centers, </t>
<t> WAN optimization between mobile phones through access nodes to/from Data center (E.g Riverbed WAN), </t>
<t> Application placement optimization using optimized DNS and DCHP VNFs, </t>
<t> Application placement optimization to minimize data transfer.</t>
</list> </t>
<t> Deployment of multi-vendor interoperability VNF services requires protocols and
interfaces to VNF Pools that VNF Managers can access. Enterprises and Carriers
have indicated their desire to allow the multi-vendor promise of SDN to be
realized in the VNF functions. </t>
<t> </t>
</section>
<section title="VNF Problems" toc="default">
<t> </t>
<t> VNF in constrained environments encounters the following types of problems: shared risk during VNF failures,
VNF instance transition, backup and state synchronization of VNF within VNF sets, appropriate placement
of VNF, reliable transport, and and multi-tenancy issues. </t>
<t> (Note: The VNF Problem statement <xref target="I-D.zong-vnfpool-problem-statement"/>
has not included multi-tenancy issues. </t>
<t> </t>
<t>Shared risk group </t>
<t> Shared risk groups occur when different VNF instances are built on top of the same instance of
a virtualized platform (E.g. hypervisor). When a hypervisor fails, all the VNF instances
on the same hypervisor will fail, and service chains with this hypervisor VNFs in the remote
chain will fail. Several concurrent services will fail when a hypervisor fails. If a fail and
a restart occur quickly, it may placed substantial load on the network as effective VFN chains cause
other nodes to be impacted.</t>
<t> </t>
<t> A VNF instance may encounter varying conditions on available resources during hypervisor load,
resource contention from other VNFs, VMs or application programs running. The resources may be
unavailable due contention with other programs placing load on the hypervisor, or
hardware failures, software failure, or DOS. </t>
<t> </t>
<t>VNF instance transition </t>
<t></t>
<t> If the VNF is unable to get the appropriate resources, the VNF meta-controller/manager may decide to migrate the
function to another hypervisor or another portion of the network. Appropriate resources may
include CPU resources, storage resources, special hardware resources, memory, and network
resources. Another reason for varying conditions of resources is the need to add additional
VNF to provide the appropriate level processing. For example, if additional in-depth analysis
of a data pattern in a traffic flow was determine further security actions, another VNF set
with DPI inspection and analysis might be created.
</t>
<t> </t>
<t>Backup and state synchronization </t>
<t> </t>
<t> Backup systems are needed for any system requiring high reliability or high
availability. Virtualized network services desired by customers may
include network services critical to security
of a network, user service levels, or insuring continued network availability
during network outages. Planned network outages require transition
of virtualized network services to other portions of the network. Transitions during
planned outages have two cycles: transition before outage, transition after outage.</t>
<t> Other than VNF transition, VNF instances will fail due to either hardware or
software failure in various levels such as hypervisor, VM or even program.
During a software failure, the VNF functions or group of functions may expand
to synchronize state, handoff processes, and announce backup. This state synchronization
may be limited to one hypervisor or spread across several hypervisors. </t>
<t> Multi-tenancy </t>
<t> When different users cohabitate the same VNFs or different
VNFs cohabitate the same hypervisors, cohabitation may cause conflicts.
Just as different human roommates sharing a common
kitchen facilities, may have different traffic patterns so do different users utilizing
the common VNFs. To stretch the metaphor, suppose one roommate wants to clean cooking
pot immediately after use while the second roommate wants to wash cooking pots at the end
of his/her cooking preparation. At some point, the roommates might contend for the sink
to wash dishes. In the same way, data flows wanting to share a Deep Packet Inspection (DPI)
engine may find that cohabitation in the multi-tenant DPI may cause issues. Different
levels of reliability will also impact how multiple tenants share their resources.
Resource pools allow both VNFs to get the common resource when desired by
virtualizing it. </t>
<t> </t>
</section>
</section>
<section title="Cloud Bursting Use Case" toc="default">
<t> </t>
<t>Description: </t>
<t></t>
<t>Three cases of cloud bursting exist. Public clouds adding more resources upon demand.
Private clouds adding more resources upon demand from private cloud resources. Private clouds
adding more resources from the public cloud. In the public/private cloud, the orchestration
system looks within pools of additional resources to fit the request for more resources for
a particular time. Verizon provided examples of cloud bursing at ONS 2012, and Terremark
utilizes cloud bursing to obtain more resources
(http://www.terremark.com/services/it-infrastructure/cloud-services/enterprise-cloud/architecture/)
operating over open-source hypervisors (2012, 2013).
</t>
<t> Resource pools with VMs that do a specific function (VNF or processing) within the
operate to configure virtual switches, routers, and transport process (TCP/STCP)
via standard interfaces (libvirt, CLI, REST, and JASON). The following is a list of functions
may use that cloud bursting operators have been known to use pools for;
</t>
<t></t>
<t><list style = "symbols">
<t> Virtual Machines (VMs) for application processing </t>
<t> VMs for remote storage drops </t>
<t> VMs for virtual firewall </t>
<t> VMS for DPI or DDOS </t>
<t> VMs specialized DNS that controls private/public cloud move </t>
<t> VMs for movement of data and applications within Cloud (Private/Public) or between clouds </t>
<t> VMs for VPN to user </t>
</list></t>
<t> </t>
<t>Why VNF Pools: Bursty nature of action of Cloud Bursting requires being able to
pre-allocate pools of VNF instances prior to use. Multi-vendor interoperable VNF Pools
allows Data Center operators in Enterprise and Carriers to avoid the single-source
for purchasing and single-code source software-bug failures. </t>
</section>
<section title="Stateful Parental Controls" toc="default">
<t> </t>
<t>Description: </t>
<t> </t>
<t> Parental content filters are targeted filters that are installed based
on an identification of a user. When the centralized controller detects the
User (via traffic pattern, role identification (ABFAB, HTTP)),
SDN installs the appropriate software to guarantee filters.
Two types of security exist: authentication and authorization. In
authentication, ACL and other port based filtering is set per customer
for the user. This filtering may block, prioritize, or transfer to a
blackhole recording device different traffic. In authorization, the
systems create a web of trust via an identity server (for HTTP 1.0 SAML
template defined by OASIS and IETF ABFAB information for non-http).
</t>
<t> </t>
<t> The following is a list of some of the VNFs associated who might use pool facilities: </t>
<t> <list style = "symbols">
<t> VNF(s) for open source DPIs (snort, etc) </t>
<t> VNFs for specialized DPI inspection </t>
<t> VNFs for probes on hypervisors" </t>
<t> VNFs for depositing configuration in SDN OFS switches, and
non-SDN switches, routers, firewalls, access nodes </t>
<t> VNF(s) for firewall </t>
<t> VNFs for DDOS </t>
<t> VNFs for specialized DNS/DHCP services after private/public cloud move </t>
<t> VNFs for movement within Cloud (Private/Public) or between clouds </t>
<t> VNF(s) for VPN to user identification</t>
</list> </t>
<t> </t>
<t>Why VNF Pools: Bursty nature of user access that is data dependent requires being able to
pre-allocate pools of services prior to use. Multi-vendor interoperable VNF Pools
Enterprise and Carriers to avoid the single-source access devices
for purchasing and single-code source software-bug failures in access nodes. </t>
</section >
<section title="Load balancer" toc="default">
<t>Description: </t>
<t> </t>
<t> Load balancers (such as Riverbed or Cisco) look to balance traffic different layers of the stack (L1-L7).
SDN meta controllers (OpenDaylight, Vyatta) monitor work with the time-critical OTT control process
(which creates and manages the OTT VPNs (L2/L3/MPLS)) to determine where the load is at any
specific time, and to track it over time. The SDN orchestrators work with the
SDN OTT control process to adjust to readjust the load at L1-L7.
</t>
<t></t>
<t> The VNF functions that use resource pools in the load balancing service are: </t>
<t> <list style = "symbols">
<t> VNFs for probes in all devices (mobile phone, ipad, access devices, vswitch, vrouter, tcp optimizer,
DPI, hypervisors, VMs dumming storage, VMs creating the network;</t>
<t> VNFs for depositing configuration in SDN OFS switches, and
non-SDN switches, routers, firewalls, access nodes; </t>
<t> VNFs for firewall; </t>
<t> VNFs for Traffic capacity/load balance calculation; </t>
<t> VNFs running orchestrator monitor/change algorithms; </t>
<t> VNFs for traffic movement within Cloud (Private/Public) or between clouds to balance load; and</t>
<t> VNFs for VPN to user identification.</t>
</list></t>
<t>Why VNF Pools: True end-to-end Load balancing requires a load balancing across multiple layers.
with VNF pools to support different functions. Multi-vendors solutions will allow
meta controllers to balance traffic to reduce costs in networks.
Current Enterprise customers find the load balancing operates with TCP WAN
optimization to utilize all network bandwidth effectively. </t>
</section>
<section title="Android phone TCP WAN optimization" toc="default">
<t>Description: </t>
<t> </t>
<t> Android phones and Android tablets often communicate across the
LTE/WiFi connections. Optimization of the link for the low-bandwidth
of LTE or Wifi connections, and the switch between LTE and WiFi
requires monitoring of traffic, choosing link, optimizing TCP
(Window and removing duplicates).
</t>
<t> </t>
<t> The VNFs that use resource pools in this application include: </t>
<t> <list style = "symbols">
<t> VNFs for probes in all devices (mobile phone, mobile pads, Wifi enabled nodes, LTE IP RAN notes)</t>
<t> VNFs for depositing configuration in SDN access nodes (Wifi or LTE) </t>
<t> VNFs for to handle remote phone parameter adjustments; </t>
<t> VNFs to do firewalls (E.g traffic not allowed over LTE due to customer policy); </t>
<t> VNFs for TCP data de-duplication process; </t>
<t> VNFs for Traffic capacity/load balance calculation (see Football stadium problem below); </t>
<t> VNFs for best processing of Video traffic or best network to pull Video traffic from; </t>
<t> VNFs for VMs for VPN to user identification; and </t>
<t> VNFs to interface to secure data processes. </t>
</list> </t>
<t> </t>
<t> One scenario to consider is the football stadium scenario. A person takes the
IPAD to watch the close up replays or send email. During fourth quarter,
the person receive an urgent call to go home and walks with the IPAD down
the street to the metro-system to return home. On the way, the person is
utilizing the IPAD to send mail, watch the football game, and do Skype calls.
</t>
<t>Why VNF Pools: Phones systems do not want a single vendor for all features.
Multiple interoperable access nodes and Android pad/tablet implementations require
these VNF pools. </t>
</section>
<section title="SOHO device optimization" toc="default">
<t>Description: </t>
<t> </t>
<t> SOHO devices using SDN VM technology must balance
traffic movement between small cells (WiFi or femtocells).
Access policies must be configured for restriction on this policy.
</t>
<t> </t>
<t> The VNFs that use resource pools in this application are: </t>
<t> <list style = "symbols">
<t> VNFs for probes in all devices (mobile phone, mobile pads, WiFi enabled nodes, LTE or femtocells)</t>
<t> VNFs for depositing configuration in SDN access nodes (Wifi, L),
VNFs for handling remote phone parameter adjustments; </t>
<t> vNFs for firewall (traffic not allowed over LTE); </t>
<t> VNFs for TCP data de-duplication process; </t>
<t> VNFs for Traffic capacity/load balancing over single/multiple soho links; </t>
<t> VNFs to allow applications load balance across internal soho links based on traffic needs
and use policy; and </t>
<t> VNFs for VPN to user identification and security.</t>
</list> </t>
<t>Why VNF Pools: SOHO devices often need to be plug and play for different types of users.
Common VNF Pools allows development of interoperable devices that can plug and
play under a SOHO controller. </t>
<t> </t>
</section>
<section title="application scaling" toc="default">
<t>Description: </t>
<t> </t>
<t> Applications may be placed in a variety of hypervisors.
The rapid deployment of applications on services may allow
millions of applications to be available within the cloud.
Creating a effective lookup for the applications or redirecting
applications takes an Network Virtual environment that controls
DCHP, DNS, and http access rapidly. 2 Million URI references
for each access node is possible given the current growth.
</t>
<t> VNF within the cloud must scale up to handle
the VNF services required by the network infrastructure.
This includes the network information functions of
DNS, DCHP, URL processing, AAA (Diameter/Radius).
Fast enactment of these network functions allows an
on-demand creation of a multi-tennancy overlay (IETF NV03). </t>
<t> </t>
<t> The VNFs that use resource pools in this application are: </t>
<t> </t>
<t> <list style = "symbols">
<t> VNFs for AAA functions (Diameter, Radius); </t>
<t> VNFs for DNS functions; </t>
<t> VNFs for DCHP functions </t>
<t> VNFs for specialized URL/URI processing; </t>
<t> VNFs for handling remote probes on these virtual information functions; </t>
<t> VNFs for handling remote configuration of these virtual information functions; </t>
<t> VNFs for Traffic capacity/load balance calculation; </t>
<t> VNFs for determine optimum deployment of full VMs for application or
determination if data transfer to an existing application (Java Application data); </t>
<t> VNFs for VPN to user identification and permissions to use data; and </t>
<t> VNFs to determine back-up placements for applications</t>
</list> </t>
</section >
<section anchor="IANA" title="IANA Considerations">
<t>This document includes no request to IANA.</t>
</section>
<section anchor="Security" title="Security Considerations">
<t>This document has no security issues as just contains use cases.</t>
</section>
</middle>
<back>
<references title="Normative References">
&RFC2119;
</references>
<references title="Informative References">
&I-D.zong-vnfpool-problem-statement;
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