Network Working Group C. Filsfils, Ed.
Internet-Draft S. Previdi, Ed.
Intended status: Standards Track A. Bashandy
Expires: October 16, 2016 Cisco Systems, Inc.
B. Decraene
S. Litkowski
Orange
April 14, 2016
Segment Routing interworking with LDP
draft-ietf-spring-segment-routing-ldp-interop-01
Abstract
A Segment Routing (SR) node steers a packet through a controlled set
of instructions, called segments, by prepending the packet with an SR
header. A segment can represent any instruction, topological or
service-based. SR allows to enforce a flow through any topological
path and service chain while maintaining per-flow state only at the
ingress node to the SR domain.
The Segment Routing architecture can be directly applied to the MPLS
data plane with no change in the forwarding plane. This drafts
describes how Segment Routing operates in a network where LDP is
deployed and in the case where SR-capable and non-SR-capable nodes
coexist.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on October 16, 2016.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. SR/LDP Ship-in-the-night coexistence . . . . . . . . . . . . 3
2.1. MPLS2MPLS co-existence . . . . . . . . . . . . . . . . . 5
2.2. IP2MPLS co-existence . . . . . . . . . . . . . . . . . . 6
3. Migration from LDP to SR . . . . . . . . . . . . . . . . . . 6
4. SR and LDP Interworking . . . . . . . . . . . . . . . . . . . 7
4.1. LDP to SR . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2. SR to LDP . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Leveraging SR benefits for LDP-based traffic . . . . . . . . 9
5.1. Eliminating Targeted LDP Session . . . . . . . . . . . . 11
5.2. Guaranteed FRR coverage . . . . . . . . . . . . . . . . . 12
6. Inter-AS Option C, Carrier's Carrier and Seamless MPLS . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Manageability Considerations . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 14
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
11. Contributors' Addresses . . . . . . . . . . . . . . . . . . . 14
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
12.1. Normative References . . . . . . . . . . . . . . . . . . 14
12.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Segment Routing, as described in [I-D.ietf-spring-segment-routing],
can be used on top of the MPLS data plane without any modification as
described in [I-D.ietf-spring-segment-routing-mpls].
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Segment Routing control plane can co-exist with current label
distribution protocols such as LDP.
This draft outlines the mechanisms through which SR interworks with
LDP in cases where a mix of SR-capable and non-SR-capable routers co-
exist within the same network.
Section 2 describes the co-existence of SR with other MPLS Control
Plane. Section 3 documents a method to migrate from LDP to SR-based
MPLS tunneling. Section 4 documents the interworking between SR and
LDP in the case of non-homogeneous deployment. Section 5 describes
how a partial SR deployment can be used to provide SR benefits to
LDP-based traffic. Section 6 describes a possible application of SR
in the context of inter-domain MPLS use-cases.
2. SR/LDP Ship-in-the-night coexistence
We call "MPLS Control Plane Client (MCC)" any control plane protocol
installing forwarding entries in the MPLS data plane. SR, LDP, RSVP-
TE, BGP 3107, VPNv4, etc are examples of MCCs.
An MCC, operating at node N, must ensure that the incoming label it
installs in the MPLS data plane of Node N has been uniquely allocated
to himself.
Thanks to the defined segment allocation rule and specifically the
notion of the Segment Routing Global Block (SRGB, as defined in
[I-D.ietf-spring-segment-routing]), SR can co-exist with any other
MCC.
This is clearly the case for the adjacency segment: it is a local
label allocated by the label manager, as for any MCC.
This is clearly the case for the prefix segment: the label manager
allocates the SRGB set of labels to the SR MCC client and the
operator ensures the unique allocation of each global prefix segment/
label within the allocated SRGB set.
Note that this static label allocation capability of the label
manager has been existing for many years across several vendors and
hence is not new. Furthermore, note that the label-manager ability
to statically allocate a range of labels to a specific application is
not new either. This is required for MPLS-TP operation. In this
case, the range is reserved by the label manager and it is the MPLS-
TP NMS (acting as an MCC) that ensures the unique allocation of any
label within the allocated range and the creation of the related MPLS
forwarding entry.
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Let us illustrate an example of ship-in-the-night (SIN) coexistence.
PE2 PE4
\ /
PE1----A----B---C---PE3
Figure 1: SIN coexistence
The EVEN VPN service is supported by PE2 and PE4 while the ODD VPN
service is supported by PE1 and PE3. The operator wants to tunnel
the ODD service via LDP and the EVEN service via SR.
This can be achieved in the following manner:
The operator configures PE1, PE2, PE3, PE4 with respective
loopbacks 192.0.2.201/32, 192.0.2.202/32, 192.0.2.203/32,
192.0.2.204/32. These PE's advertised their VPN routes with next-
hop set on their respective loopback address.
The operator configures A, B, C with respective loopbacks
192.0.2.1/32, 192.0.2.2/32, 192.0.2.3/32.
The operator configures PE2, A, B, C and PE4 with SRGB [100, 300].
The operator attach the respective Node Segment Identifiers (Node-
SID's, as defined in [I-D.ietf-spring-segment-routing]): 202, 101,
102, 103 and 204 to the loopbacks of nodes PE2, A, B, C and PE4.
The Node-SID's are configured to request penultimate-hop-popping.
PE1, A, B, C and PE3 are LDP capable.
PE1 and PE3 are not SR capable.
PE3 sends an ODD VPN route to PE1 with next-hop 192.0.2.203 and VPN
label 10001.
From an LDP viewpoint: PE1 received an LDP label binding (1037) for
FEC 192.0.2.203/32 from its nhop A. A received an LDP label binding
(2048) for that FEC from its nhop B. B received an LDP label binding
(3059) for that FEC from its nhop C. C received implicit-null LDP
binding from its next-hop PE3.
As a result, PE1 sends its traffic to the ODD service route
advertised by PE3 to next-hop A with two labels: the top label is
1037 and the bottom label is 10001. A swaps 1037 with 2048 and
forwards to B. B swaps 2048 with 3059 and forwards to C. C pops
3059 and forwards to PE3.
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PE4 sends an EVEN VPN route to PE2 with next-hop 192.0.2.204 and VPN
label 10002.
From an SR viewpoint: PE1 maps the IGP route 192.0.2.204/32 onto
Node-SID 204; A swaps 204 with 204 and forwards to B; B swaps 204
with 204 and forwards to C; C pops 204 and forwards to PE4.
As a result, PE2 sends its traffic to the VPN service route
advertised by PE4 to next-hop A with two labels: the top label is 204
and the bottom label is 10002. A swaps 204 with 204 and forwards to
B. B swaps 204 with 204 and forwards to C. C pops 204 and forwards
to PE4.
The two modes of MPLS tunneling co-exist.
The ODD service is tunneled from PE1 to PE3 through a continuous
LDP LSP traversing A, B and C.
The EVEN service is tunneled from PE2 to PE4 through a continuous
SR node segment traversing A, B and C.
2.1. MPLS2MPLS co-existence
We want to highlight that several MPLS2MPLS entries can be installed
in the data plane for the same prefix.
Let us examine A's MPLS forwarding table as an example:
Incoming label: 1037
- outgoing label: 2048
- outgoing nhop: B
Note: this entry is programmed by LDP for 192.0.2.203/32
Incoming label: 203
- outgoing label: 203
- outgoing nhop: B
Note: this entry is programmed by SR for 192.0.2.203/32
These two entries can co-exist because their incoming label is
unique. The uniqueness is guaranteed by the label manager allocation
rules.
The same applies for the MPLS2IP forwarding entries.
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2.2. IP2MPLS co-existence
By default, we propose that if both LDP and SR propose an IP2MPLS
entry for the same IP prefix, then the LDP route is selected.
A local policy on a router MUST allow to prefer the SR-provided
IP2MPLS entry.
Note that this policy may be locally defined. There is no
requirement that all routers use the same policy.
3. Migration from LDP to SR
PE2 PE4
\ /
PE1----P5--P6--P7---PE3
Figure 2: Migration
Several migration techniques are possible. We describe one technique
inspired by the commonly used method to migrate from one IGP to
another.
T0: all the routers run LDP. Any service is tunneled from an ingress
PE to an egress PE over a continuous LDP LSP.
T1: all the routers are upgraded to SR. They are configured with the
SRGB range [100, 300]. PE1, PE2, PE3, PE4, P5, P6 and P7 are
respectively configured with the node segments 101, 102, 103, 104,
105, 106 and 107 (attached to their service-recursing loopback).
At this time, the service traffic is still tunneled over LDP LSP.
For example, PE1 has an SR node segment to PE3 and an LDP LSP to
PE3 but by default, as seen earlier, the LDP IP2MPLS encapsulation
is preferred.
T2: the operator enables the local policy at PE1 to prefer SR IP2MPLS
encapsulation over LDP IP2MPLS.
The service from PE1 to any other PE is now riding over SR. All
other service traffic is still transported over LDP LSP.
T3: gradually, the operator enables the preference for SR IP2MPLS
encapsulation across all the edge routers.
All the service traffic is now transported over SR. LDP is still
operational and services could be reverted to LDP.
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However, any traffic switched through LDP entries will still
suffer from LDP-IGP synchronization.
T4: LDP is unconfigured from all routers.
4. SR and LDP Interworking
In this section, we analyze a use-case where SR is available in one
part of the network and LDP is available in another part. We
describe how a continuous MPLS tunnel can be built throughout the
network.
PE2 PE4
\ /
PE1----P5--P6--P7--P8---PE3
Figure 3: SR and LDP Interworking
Let us analyze the following example:
P6, P7, P8, PE4 and PE3 are LDP capable.
PE1, PE2, P5 and P6 are SR capable. PE1, PE2, P5 and P6 are
configured with SRGB (100, 200) and respectively with node
segments 101, 102, 105 and 106.
A service flow must be tunneled from PE1 to PE3 over a continuous
MPLS tunnel encapsulation. We need SR and LDP to interwork.
4.1. LDP to SR
In this section, we analyze a right-to-left traffic flow.
PE3 has learned a service route whose nhop is PE1. PE3 has an LDP
label binding from the nhop P8 for the FEC "PE1". Hence PE3 sends
its service packet to P8 as per classic LDP behavior.
P8 has an LDP label binding from its nhop P7 for the FEC "PE1" and
hence P8 forwards to P7 as per classic LDP behavior.
P7 has an LDP label binding from its nhop P6 for the FEC "PE1" and
hence P7 forwards to P6 as per classic LDP behavior.
P6 does not have an LDP binding from its nhop P5 for the FEC "PE1".
However P6 has an SR node segment to the IGP route "PE1". Hence, P6
forwards the packet to P5 and swaps its local LDP-label for FEC "PE1"
by the equivalent node segment (i.e. 101).
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P5 pops 101 (assuming PE1 advertised its node segment 101 with the
penultimate-pop flag set) and forwards to PE1.
PE1 receives the tunneled packet and processes the service label.
The end-to-end MPLS tunnel is built from an LDP LSP from PE3 to P6
and the related node segment from P6 to PE1.
4.2. SR to LDP
In this section, we analyze the left-to-right traffic flow.
We assume that the operator configures P5 to act as a Segment Routing
Mapping Server (SRMS) and advertises the following mappings: (P7,
107), (P8, 108), (PE3, 103) and (PE4, 104).
These mappings are advertised as Remote-Binding SID with Flag TBD.
The mappings advertised by an SR mapping server result from local
policy information configured by the operator. If PE3 had been SR
capable, the operator would have configured PE3 with node segment
103. Instead, as PE3 is not SR capable, the operator configures that
policy at the SRMS and it is the latter which advertises the mapping.
Multiple SRMS servers can be provisioned in a network for redundancy.
The mapping server advertisements are only understood by the SR
capable routers. The SR capable routers install the related node
segments in the MPLS data plane exactly like if the node segments had
been advertised by the nodes themselves.
For example, PE1 installs the node segment 103 with nhop P5 exactly
as if PE3 had advertised node segment 103.
PE1 has a service route whose nhop is PE3. PE1 has a node segment
for that IGP route: 103 with nhop P5. Hence PE1 sends its service
packet to P5 with two labels: the bottom label is the service label
and the top label is 103.
P5 swaps 103 for 103 and forwards to P6.
P6's next-hop for the IGP route "PE3" is not SR capable (P7 does not
advertise the SR capability). However, P6 has an LDP label binding
from that next-hop for the same FEC (e.g. LDP label 1037). Hence,
P6 swaps 103 for 1037 and forwards to P7.
P7 swaps this label with the LDP-label received from P8 and forwards
to P8.
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P8 pops the LDP label and forwards to PE3.
PE3 receives the tunneled packet and processes the service label.
The end-to-end MPLS tunnel is built from an SR node segment from PE1
to P6 and an LDP LSP from P6 to PE3.
Note: SR mappings advertisements cannot set Penultimate Hop Popping.
In the previous example, P6 requires the presence of the segment 103
such as to map it to the LDP label 1037. For that reason, the P flag
available in the Prefix-SID is not available in the Remote-Binding
SID.
5. Leveraging SR benefits for LDP-based traffic
SR can be deployed such as to enhance LDP transport. The SR
deployment can be limited to the network region where the SR benefits
are most desired.
In Figure 4, let us assume:
All link costs are 10 except FG which is 30.
All routers are LDP capable.
X, Y and Z are PE's participating to an important service S.
The operator requires 50msec link-based Fast Reroute (FRR) for
service S.
A, B, C, D, E, F and G are SR capable.
X, Y, Z are not SR capable, e.g. as part of a staged migration
from LDP to SR, the operator deploys SR first in a sub-part of the
network and then everywhere.
X
|
Y--A---B---E--Z
| | \
D---C--F--G
30
Figure 4: Leveraging SR benefits for LDP-based-traffic
The operator would like to resolve the following issues:
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To protect the link BA along the shortest-path of the important
flow XY, B requires a Remote LFA (RLFA, [RFC7490]) repair tunnel
to D and hence a targeted LDP session from B to D. Typically,
network operators prefer avoiding these dynamically established
multi-hop LDP sessions in order to reduce the number of protocols
running in the network and hence simplify network operations.
There is no LFA/RLFA solution to protect the link BE along the
shortest path of the important flow XZ. The operator wants a
guaranteed link-based FRR solution.
The operator can meet these objectives by deploying SR only on A, B,
C, D, E, F and G:
The operator configures A, B, C, D, E, F and G with SRGB (100,
200) and respective node segments 101, 102, 103, 104, 105, 106 and
107.
The operator configures D as an SR Mapping Server with the
following policy mapping: (X, 201), (Y, 202), (Z, 203).
Each SR node automatically advertises local adjacency segment for
its IGP adjacencies. Specifically, F advertises adjacency segment
9001 for its adjacency FG.
A, B, C, D, E, F and G keep their LDP capability and hence the flows
XY and XZ are transported over end-to-end LDP LSP's.
For example, LDP at B installs the following MPLS data plane entries:
Incoming label: local LDB label bound by B for FEC Y
Outgoing label: LDP label bound by A for FEC Y
Outgoing nhop: A
Incoming label: local LDB label bound by B for FEC Z
Outgoing label: LDP label bound by E for FEC Z
Outgoing nhop: E
The novelty comes from how the backup chains are computed for these
LDP-based entries. While LDP labels are used for the primary nhop
and outgoing labels, SR information is used for the FRR construction.
In steady state, the traffic is transported over LDP LSP. In
transient FRR state, the traffic is backup thanks to the SR enhanced
capabilities.
The RLFA paths are dynamically pre-computed as defined in [RFC7490].
Typically, implementations allow to enable RLFA mechanism through a
simple configuration command that triggers both the pre-computation
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and installation of the repair path. The details on how RLFA
mechanisms are implemented and configured is outside the scope of
this document and not relevant to the aspects of SR/LDP interwork
explained in this document.
This helps meet the requirements of the operator:
Eliminate targeted LDP session.
Guaranteed FRR coverage.
Keep the traffic over LDP LSP in steady state.
Partial SR deployment only where needed.
5.1. Eliminating Targeted LDP Session
B's MPLS entry to Y becomes:
- Incoming label: local LDB label bound by B for FEC Y
Outgoing label: LDP label bound by A for FEC Y
Backup outgoing label: SR node segment for Y {202}
Outgoing nhop: A
Backup nhop: repair tunnel: node segment to D {104}
with outgoing nhop: C
It has to be noted that D is selected as Remote Free Alternate
(R-LFA) as defined in [RFC7490].
In steady-state, X sends its Y-destined traffic to B with a top label
which is the LDP label bound by B for FEC Y. B swaps that top label
for the LDP label bound by A for FEC Y and forwards to A. A pops the
LDP label and forwards to Y.
Upon failure of the link BA, B swaps the incoming top-label with the
node segment for Y (202) and sends the packet onto a repair tunnel to
D (node segment 104). Thus, B sends the packet to C with the label
stack {104, 202}. C pops the node segment 104 and forwards to D. D
swaps 202 for 202 and forwards to A. A's nhop to Y is not SR capable
and hence A swaps the incoming node segment 202 to the LDP label
announced by its next-hop (in this case, implicit null).
After IGP convergence, B's MPLS entry to Y will become:
- Incoming label: local LDB label bound by B for FEC Y
Outgoing label: LDP label bound by C for FEC Y
Outgoing nhop: C
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And the traffic XY travels again over the LDP LSP.
Conclusion: the operator has eliminated the need for targeted LDP
sessions (no longer required) and the steady-state traffic is still
transported over LDP. The SR deployment is confined to the area
where these benefits are required.
Despite that in general, an implementation would not require a manual
configuration of LDP Targeted sessions however, it is always a gain
if the operator is able to reduce the set of protocol sessions
running on the network infrastructure.
5.2. Guaranteed FRR coverage
B's MPLS entry to Z becomes:
- Incoming label: local LDB label bound by B for FEC Z
Outgoing label: LDP label bound by E for FEC Z
Backup outgoing label: SR node segment for Z {203}
Outgoing nhop: E
Backup nhop: repair tunnel to G: {106, 9001}
G is reachable from B via the combination of a
node segment to F {106} and an adjacency segment
FG {9001}
Note that {106, 107} would have equally work.
Indeed, in many case, P's shortest path to Q is
over the link PQ. The adjacency segment from P to
Q is required only in very rare topologies where
the shortest-path from P to Q is not via the link
PQ.
In steady-state, X sends its Z-destined traffic to B with a top label
which is the LDP label bound by B for FEC Z. B swaps that top label
for the LDP label bound by E for FEC Z and forwards to E. E pops the
LDP label and forwards to Z.
Upon failure of the link BE, B swaps the incoming top-label with the
node segment for Z (203) and sends the packet onto a repair tunnel to
G (node segment 106 followed by adjacency segment 9001). Thus, B
sends the packet to C with the label stack {106, 9001, 203}. C pops
the node segment 106 and forwards to F. F pops the adjacency segment
9001 and forwards to G. G swaps 203 for 203 and forwards to E. E's
nhop to Z is not SR capable and hence E swaps the incoming node
segment 203 for the LDP label announced by its next-hop (in this
case, implicit null).
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After IGP convergence, B's MPLS entry to Z will become:
- Incoming label: local LDB label bound by B for FEC Z
Outgoing label: LDP label bound by C for FEC Z
Outgoing nhop: C
And the traffic XZ travels again over the LDP LSP.
Conclusion: the operator has eliminated its second problem:
guaranteed FRR coverage is provided. The steady-state traffic is
still transported over LDP. The SR deployment is confined to the
area where these benefits are required.
6. Inter-AS Option C, Carrier's Carrier and Seamless MPLS
In inter-AS Option C, two interconnected ASes sets up inter-AS MPLS
connectivity. SR may be independently deployed in each AS.
PE1---R1---B1---B2---R2---PE2
<-----------> <----------->
AS1 AS2
Figure 5: Inter-AS Option C
In Inter-AS Option C [RFC4364], B2 advertises to B1 a BGP3107 route
for PE2 and B1 reflects it to its internal peers, such as PE1. PE1
learns from a service route reflector a service route whose nhop is
PE2. PE1 resolves that service route on the BGP3107 route to PE2.
That BGP3107 route to PE2 is itself resolved on the AS1 IGP route to
B1.
If AS1 operates SR, then the tunnel from PE1 to B1 is provided by the
node segment from PE1 to B1.
PE1 sends a service packet with three labels: the top one is the node
segment to B1, the next-one is the BGP3107 label provided by B1 for
the route "PE2" and the bottom one is the service label allocated by
PE2.
7. IANA Considerations
This document does not introduce any new codepoint.
8. Manageability Considerations
TBD
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9. Security Considerations
TBD
10. Acknowledgements
We would like to thank Pierre Francois and Ruediger Geib for their
contribution to the content of this document.
11. Contributors' Addresses
Edward Crabbe
Individual
Email: edward.crabbe@gmail.com
Igor Milojevic
Email: milojevicigor@gmail.com
Saku Ytti
TDC
Email: saku@ytti.fi
Rob Shakir
Individual
Email: rjs@rob.sh
Martin Horneffer
Deutsche Telekom
Email: Martin.Horneffer@telekom.de
Wim Henderickx
Alcatel-Lucent
Email: wim.henderickx@alcatel-lucent.com
Jeff Tantsura
Ericsson
Email: Jeff.Tantsura@ericsson.com
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
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[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <http://www.rfc-editor.org/info/rfc4364>.
12.2. Informative References
[I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
and R. Shakir, "Segment Routing Architecture", draft-ietf-
spring-segment-routing-07 (work in progress), December
2015.
[I-D.ietf-spring-segment-routing-mpls]
Filsfils, C., Previdi, S., Bashandy, A., Decraene, B.,
Litkowski, S., Horneffer, M., Shakir, R., Tantsura, J.,
and E. Crabbe, "Segment Routing with MPLS data plane",
draft-ietf-spring-segment-routing-mpls-04 (work in
progress), March 2016.
[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015,
<http://www.rfc-editor.org/info/rfc7490>.
Authors' Addresses
Clarence Filsfils (editor)
Cisco Systems, Inc.
Brussels
BE
Email: cfilsfil@cisco.com
Stefano Previdi (editor)
Cisco Systems, Inc.
Via Del Serafico, 200
Rome 00142
Italy
Email: sprevidi@cisco.com
Filsfils, et al. Expires October 16, 2016 [Page 15]
Internet-Draft Segment Routing and LDP April 2016
Ahmed Bashandy
Cisco Systems, Inc.
170, West Tasman Drive
San Jose, CA 95134
US
Email: bashandy@cisco.com
Bruno Decraene
Orange
FR
Email: bruno.decraene@orange.com
Stephane Litkowski
Orange
FR
Email: stephane.litkowski@orange.com
Filsfils, et al. Expires October 16, 2016 [Page 16]
