ICN Ping Protocol Specification
draft-mastorakis-icnrg-icnping-01
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| Authors | Spyridon Mastorakis , Jim Gibson , Ilya Moiseenko , Ralph Droms , David R. Oran | ||
| Last updated | 2017-02-23 | ||
| Replaced by | draft-irtf-icnrg-icnping | ||
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draft-mastorakis-icnrg-icnping-01
ICNRG S. Mastorakis
Internet-Draft UCLA
Intended status: Experimental J. Gibson
Expires: August 27, 2017 I. Moiseenko
Cisco Systems
R. Droms
D. Oran
February 23, 2017
ICN Ping Protocol Specification
draft-mastorakis-icnrg-icnping-01
Abstract
This document presents the design of an ICN Ping protocol. It
includes the operations both on the client and the forwarder side.
The design expresses the views of the authors and does not represent
the views of the Named Data Networking Project Team.
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
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This Internet-Draft will expire on August 27, 2017.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Background on IP-Based Ping Operation . . . . . . . . . . . . 3
3. Ping Functionality Challenges and Opportunities in ICN . . . 3
4. ICN Ping Echo CCNx Packet Formats . . . . . . . . . . . . . . 5
4.1. ICN Ping Echo Request CCNx Packet Format . . . . . . . . 5
4.2. Ping Echo Reply CCNx Packet Format . . . . . . . . . . . 8
5. ICN Ping Echo NDN Packet Formats . . . . . . . . . . . . . . 11
5.1. ICN Ping Echo Request NDN Packet Format . . . . . . . . . 11
5.2. Ping Echo Reply NDN Packet Format . . . . . . . . . . . . 12
6. Forwarder Handling . . . . . . . . . . . . . . . . . . . . . 13
7. Protocol Operation For Locally-Scoped Namespaces . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. Ping Client Application (Consumer) Operation . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
Determining data plane reachability to a destination and taking
coarse performance measurements of round trip time are fundamental
facilities for network administration and troubleshooting. In IP,
where routing and forwarding are based on IP addresses, ICMP echo and
ICMP echo response are the protocol mechanisms used for this purpose,
generally exercised through the familiar ping utility. In ICN, where
routing and forwarding are based on name prefixes, the ability to
determine reachability of names is required.
This document proposes protocol mechanisms for a ping equivalent in
ICN networks. A non-normative appendix suggests useful properties
for an ICN ping client application, analogous to IP ping, that
originates echo requests and process echo replies.
1.1. 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 [RFC2119].
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2. Background on IP-Based Ping Operation
In IP-based ping, an IP address is specified, either directly, or via
translation of a domain name through DNS. The ping client
application sends a number of ICMP Echo Request packets with the
specified IP address as the IP destination address and an IP address
from the client's host as the IP source address.
An ICMP Echo Request is forwarded across the network based on its
destination IP address. If it eventually reaches the destination,
the destination responds by sending back an ICMP Echo Reply packet to
the IP source address from the ICMP Echo Request.
If an ICMP Echo Request does not reach the destination or the Echo
reply is lost, the ping client times out. Any ICMP error messages,
such as "no route to destination", generated by the ICMP Echo Request
message are returned to the client and reported.
3. Ping Functionality Challenges and Opportunities in ICN
In ICN protocols (e.g., NDN and CCNx), the communication paradigm is
based exclusively on named objects. An Interest is forwarded across
the network based on its name. Eventually, it retrieves a content
object either from a producer application or some forwarder's Content
Store (CS).
IP-based ping was built as an add-on on top of an already existing
network architecture. In ICN, we have the opportunity to incorporate
diagnostic mechanisms directly in the network layer protocol, and
hopefully provide more powerful diagnostic capability than can be
realized through the layered ICMP Echo approach.
An ICN network differs from an IP network in at least 4 important
ways:
o IP identifies interfaces to an IP network with a fixed-length
number, and delivers IP packets to one or more interfaces. ICN
identifies units of data in the network with a variable length
name consisting of a list of components.
o An IP-based network depends on the IP packets having source IP
addresses that are used as the destination address for replies.
On the other hand, ICN Interests do not have source addresses and
they are forwarded based on names, which do not refer to a unique
end-point. Data packets follow the reverse path of the Interests
based on hop-by-hop state created during Interest forwarding.
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o An IP network supports multi-path, single destination, stateless
packet forwarding and delivery via unicast, a limited form of
multi-destination selected delivery with anycast, and group-based
multi-destination delivery via multicast. In contrast, ICN
supports multi-path and multi-destination stateful Interest
forwarding and multi-destination data delivery to units of named
data. This single forwarding semantic subsumes the functions of
unicast, anycast, and multicast. As a result, consecutive (or
retransmitted) ICN Interest messages may be forwarded through an
ICN network along different paths, and may be forwarded to
different data sources (e.g., end-node applications, in-network
storage) holding a copy of the requested unit of data. This can
lead to a significant variance in round-trip times, which might
not be desirable in the case of a network troubleshooting
mechanism like ping.
o In the case of multiple Interests with the same name arriving at a
forwarder, a number of Interests may be aggregated in a common
Pending Interest Table (PIT) entry. Depending on the lifetime of
a PIT entry, the round-trip time an Interest-Data exchange might
significantly vary (e.g., it might be shorter than the full round-
trip time to reach the original content producer). To this end,
the round-trip time experienced by consumers might also vary.
These differences introduce new challenges, new opportunities and new
requirements in the design of an ICN ping protocol. Following this
communication model, a ping client should be able to express ping
echo requests with some name prefix and receive responses.
Our goals are the following:
o Test the reachability and the operation of an ICN forwarder.
o Test the reachability of an application (in the sense of whether
Interests for a prefix that it serves can be forwarded to it) and
discover the forwarder with local connectivity to (an instance of)
the application.
o Test whether a specific named object is cached in some on-path CS,
and, if so, return the corresponding forwarder.
o Perform some simple network performance measurements.
To this end, a ping name can represent:
o An administrative name that has been assigned to a forwarder.
o A name that includes an application's namespace as a prefix.
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o A named object that might reside in some in-network storage.
In order to provide stable and reliable diagnostics, it is desirable
that the packet encoding of a ping echo request enables the
forwarders to distinguish a ping from a normal Interest, while also
allowing for forwarding behavior to be as similar as possible to that
of an Interest packet. In the same way, the encoding of a ping echo
reply should allow for forwarder processing similar to that used for
data packets.
The ping protocol should also enable relatively stable round-trip
time measurements. To this end, it is important to have a mechanism
to steer consecutive ping echo requests for the same name towards a
common path.
It is also important, in the case of ping echo requests for the same
name from different sources, to have a mechanism to avoid aggregating
those requests in the PIT. To this end, we need some encoding in the
ping echo requests to make each request for a common name unique, and
hence avoid PIT aggregation and further enabling the exact matching
of a response with a particular ping packet.
4. ICN Ping Echo CCNx Packet Formats
In this section, we describe the Echo Packet Format according to the
CCNx packet format [CCNMessages], where messages exist within
outermost containments (packets). Specifically, we propose two types
of ping packets, an echo request and an echo reply packet type.
4.1. ICN Ping Echo Request CCNx Packet Format
The format of the ping echo request packet is presented below:
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | | |
| Version | EchoRequest | PacketLength |
| | | |
+---------------+---------------+---------------+---------------+
| | | | |
| HopLimit | Reserved | Flags | HeaderLength |
| | | | |
+---------------+---------------+---------------+---------------+
/ /
/ PathSteering TLV /
/ /
+---------------+---------------+---------------+---------------+
| |
| Echo Request Message TLVs |
| |
+---------------+---------------+---------------+---------------+
Echo Request CCNx Packet Format
The existing packet header fields have similar functionality to the
header fields of a CCNx Interest packet. The value of the packet
type field is Echo Request. The exact numeric value of this field
type is to be determined.
Compared to the typical format of a CCNx packet header [CCNMessages],
there is a new optional fixed header TLV added to the packet header:
o A PathSteering hop-by-hop header TLV, which is constructed hop-by-
hop in the echo reply and included in the echo request to steer
consecutive echo requests expressed by a ping client towards a
common forwarding path. An example of such a scheme is presented
in [LIPSIN].
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| PathSteering_Type | PathSteering_Length |
| | |
+---------------+---------------+---------------+---------------+
| |
| PathSteering_Value |
| |
+---------------+---------------+---------------+---------------+
PathSteering TLV
The message of an echo request is presented below:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| MessageType = 1 | MessageLength |
| | |
+---------------+---------------+---------------+---------------+
| |
| Name TLV |
| |
+---------------+---------------+---------------+---------------+
Echo Request Message Format
The echo request message is of type Interest in order to leverage the
Interest forwarding behavior provided by the network. The Name TLV
has the structure described in [CCNMessages]. The name consists of
the prefix that we would like to ping appended with a nonce typed
name component as its last component. The value of this TLV will be
a 64-bit nonce. The purpose of the nonce is to avoid Interest
aggregation and allow client matching of replies with requests. As
described below, the nonce is ignored for CS checking.
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| Nonce_Type | Nonce_Length = 8 |
| | |
+---------------+---------------+---------------+---------------+
| |
| |
| |
| Nonce_Value |
| |
| |
+---------------+---------------+---------------+---------------+
Nonce Typed Name Component TLV
4.2. Ping Echo Reply CCNx Packet Format
The format of a ping echo reply packet is presented below:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | | |
| Version | EchoReply | PacketLength |
| | | |
+---------------+---------------+---------------+---------------+
| | | |
| Reserved | Flags | HeaderLength |
| | | |
+---------------+---------------+---------------+---------------+
| |
| PathSteering TLV |
| |
+---------------+---------------+---------------+---------------+
| |
| Echo Reply Message TLVs |
| |
+---------------+---------------+---------------+---------------+
Echo Reply CCNx Packet Format
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The header of an echo reply consists of the header fields of a CCNx
Content Object and a hop-by-hop PathSteering TLV. The value of the
packet type field is Echo Reply. The exact numeric value of this
field type is to be determined. The PathSteering header TLV is as
defined for the echo request packet.
A ping echo reply message is of type Content Object, contains a Name
TLV (name of the corresponding echo request), a PayloadType TLV and
an ExpiryTime TLV with a value of 0 to indicate that echo replies
must not be cached by the network.
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| MessageType = 2 | MessageLength |
| | |
+---------------+---------------+---------------+---------------+
| |
| Name TLV |
| |
+---------------+---------------+---------------+---------------+
| |
| PayloadType TLV |
| |
+---------------+---------------+---------------+---------------+
| |
| ExpiryTime TLV |
| |
+---------------+---------------+---------------+---------------+
Echo Reply Message Format
The PayloadType TLV is presented below. It is of type
T_PAYLOADTYPE_DATA, and the data schema consists of 3 TLVs: 1) the
name of the sender of this reply (with the same structure as a CCNx
Name TLV), 2) the sender's signature of their own name (with the same
structure as a CCNx ValidationPayload TLV), 3) a TLV with return
codes to indicate what led to the generation of this reply (i.e.,
existence of a local application, a CS hit or a match with a
forwarder's administrative name as specified in Section 6).
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| T_PAYLOADTYPE_DATA | Length |
| | |
+---------------+---------------+---------------+---------------+
/ /
/ Sender's Name TLV /
/ /
+---------------+---------------+---------------+---------------+
/ /
/ Sender's Signature TLV /
/ /
+---------------+---------------+---------------+---------------+
/ /
/ Echo Reply Code TLV /
/ /
+---------------+---------------+---------------+---------------+
Echo Reply Message Format
The goal of including the name of the sender in the echo reply is to
enable the user to reach this entity directly to ask for further
management/administrative information using generic Interest-Data
exchanges after a successful verification of the sender's name.
The structure of the Echo Reply Code TLV is presented below (16-bit
value). The potential values are the following:
o 1: Indicates that the target name matched the administrative name
of a forwarder.
o 2: Indicates that the target name matched a prefix served by an
application.
o 3: Indicates that the target name matched the name of an object in
a forwarder's CS.
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+
| | |
| Echo_Reply_Code_Type | Echo_Reply_Code_Length = 2 |
| | |
+---------------+---------------+---------------+---------------+
| |
| Echo_Reply_Code_Value |
+---------------+---------------+---------------+---------------+
Echo Reply Code TLV
5. ICN Ping Echo NDN Packet Formats
In this section, we present the ICN Ping Echo Request and Reply
Format according to the NDN packet specification [NDNTLV].
5.1. ICN Ping Echo Request NDN Packet Format
An echo request is encoded as an NDN Interest packet. Its format is
the following:
EchoRequest ::= INTEREST-TYPE TLV-LENGTH
Name
MustBeFresh
Nonce
PathSteering TLV?
Echo Request NDN Packet Format
The name of an echo request consists of the prefix to be pinged, a
nonce value (it can be the value of the Nonce field) and the suffix
"ping" to denote that this Interest is a ping request.
An echo request contains a new optional field for the hop-by-hop
PathSteering TLV. The format of this field is the following:
PathSteering TLV ::= PATHSTEERING-TLV-TYPE TLV-LENGTH BYTE{8}
PathSteering TLV
Since the NDN packet format does not provide a mechanism to prevent
the network from caching specific data packets, we will use the
MustBeFresh selector for echo requests (in combination with a
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Freshness Period TLV of value 0 for echo replies) to avoid fetching
cached echo replies.
5.2. Ping Echo Reply NDN Packet Format
An echo reply is encoded as an NDN Data packet. Its format is the
following:
EchoReply ::= DATA-TLV TLV-LENGTH
PathSteering TLV
Name
MetaInfo
Content
Signature
Echo Reply NDN Packet Format
Compared to the format of a regular NDN Data packet, an echo reply
contains a PathSteering TLV field, which is not included in the
security envelope, since it might be modified in a hop-by-hop fashion
by the forwarders along the reverse path.
The name of an echo reply is the name of the corresponding echo
request, while the format of the MetaInfo field is the following:
MetaInfo ::= META-INFO-TYPE TLV-LENGTH
ContentType
FreshnessPeriod
MetaInfo TLV
The value of the ContentType TLV is 0. The same applies to the value
of the FreshnessPeriod TLV, so that the replies are treated as stale
data as soon as they are received by a forwarder.
The content of an echo reply consists of the following 2 TLVs:
Sender's name (with a structure similar as an NDN Name TLV) and Echo
Reply Code. There is no need to have a separate TLV for the sender's
signature in the content of the reply, since every NDN data packet
carries the signature of the data producer.
The Echo Reply Code TLV format is the following (with the values
specified in Section 4.2):
EchoReplyCode ::= ECHOREPLYCODE-TLV-TYPE TLV-LENGTH BYTE{2}
Echo Reply Code TLV
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6. Forwarder Handling
When a forwarder receives an echo request, it will first extract the
message's base name (i.e., the request name with the Nonce name
component excluded and the suffix "ping" in the case of an echo
request with the NDN packet format).
In some cases, the forwarder will originate an echo reply, sending
the reply downstream through the face on which the echo request was
received. An echo reply will include the forwarder's own name and
signature, and, the appropriate echo reply code based on the
condition that triggered the reply generation. It will also include
a pathSteering TLV, initially a null value (since the echo reply
originator does not forward the request and, thus, does not make a
path choice).
The forwarder generates an echo reply in the following cases:
o Assuming that a forwarder has been given one or more
administrative names, the echo request base name exactly matches
any of the forwarder's administrative name(s).
o The echo request's base name exactly matches the name of a
content-object residing in the forwarder's CS (unless the ping
client application has chosen not to receive replies due to CS
hits as specified in Appendix A).
o The echo request base name matches (in a Longest Prefix Match
manner) a FIB entry with an outgoing face referring to a local
application.
If none of the conditions to reply to the echo request are met, the
forwarder will attempt to forward the echo request upstream based on
the path steering value (if present) the results of the FIB LPM
lookup and PIT creation (based on the name including the nonce typed
name component and the suffix "ping" in the case of an echo request
with the NDN packet format). If no valid next-hop is found, an
InterestReturn is sent downstream (as with a failed attempt to
forward an ordinary Interest).
A received echo reply will be matched to an existing PIT entry as
usual. On the reverse path, the path steering TLV of an echo reply
will be updated by each forwarder to encode its next-hop choice.
When included in subsequent echo requests, this pathSteering TLV will
allow the forwarders to steer the requests along the same path.
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7. Protocol Operation For Locally-Scoped Namespaces
In this section, we elaborate on 2 alternative design approaches in
cases that the pinged prefix corresponds to a locally-scoped
namespace not directly routable from the client's local network.
The first approach leverages the NDN Link Object [SNAMP].
Specifically, the ping client attaches to the expressed request a
LINK Object that contains a number of routable name prefixes, based
on which the request can be forwarded across the Internet utill it
reaches a network region, where the request name itself is routable.
A LINK Object is created and signed by a data producer allowed to
publish data under a locally-scoped namespace. The way that a client
retrieves a LINK Object has to do with the overall network
architecture design and is out of the scope of the current draft.
Based on the current deployment of the LINK Object by the NDN team, a
forwarder at the boarder of the region, where an Interest name
becomes routable has to remove the LINK Object from the incoming
Interests. The Interest state maintained along the entire forwarding
path is based on the Interest name regardless of whether it was
forwarded based on its name or a routable prefix in the LINK Object.
The second approach is based on prepending a routable prefix to the
locally-scoped name. The resulting prefix will be the name of the
echo requests expressed by the client. In this way, a request will
be forwarded across the Internet based on the routable part of its
name. When it reaches the network region, where the original
locally-scoped name is routable, the boarder forwarder will have to
rewrite the request name and delete its routable part. There are two
conditions for a forwarder to perform this rewriting operation on a
request: 1) the routable part of the request name matches a routable
name of the network region adjacent to the forwarder (assuming that a
forwarder is aware of those names) and 2) the remaining part of the
request name is routable across the network region of this forwarder.
The state maintained along the path, where the locally-scoped name is
not routable, is based on the routable prefix along with the locally-
scoped prefix. Within the network region that the locally-scoped
prefix is routable, the state is based only on it. To ensure that
the generated replies will reach the ping client, the boarder
forwarder has also to rewrite the name of a reply and prepend the
routable prefix of the corresponding echo request.
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8. Security Considerations
To avoid reflection attacks in the case of an echo reply with the
CCNx packet format, where a compromised forwarder includes in the
reply the name of a victim forwarder to redirect the future
administrative traffic towards the victim, the forwarder that
generates a reply has to sign the name included in the payload. In
this way, the client is able to verify that the included name is
legitimate and refers to the forwarder that generated the reply.
Alternatively, the forwarder can include in the reply payload their
routable prefix(es) encoded as a signed NDN Link Object [SNAMP].
Interest flooding attack amplification is possible in the case of the
second approach to deal with locally-scoped namespaces described in
Section 7. A boarder forwarder will have to maintain extra state, so
that to prepend the right routable prefix to the name of an outgoing
reply, since the forwarder might be attached to multiple network
regions (reachable under different prefixes) or a network region
attached to this forwarder might be reachable under multiple routable
prefixes.
9. Acknowledgements
The authors would like to thank Mark Stapp for the fruitful
discussion on the objectives of ICN ping protocol.
10. References
10.1. 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>.
10.2. Informative References
[CCNMessages]
Mosko, M., Solis, I., and C. Wood, "CCNx Messages in TLV
Format.", 2016, <https://tools.ietf.org/html/draft-irtf-
icnrg-ccnxmessages-03>.
[LIPSIN] Jokela, P. and et al, "LIPSIN: line speed publish/
subscribe inter-networking, ACM SIGCOMM Computer
Communication Review 39.4: 195-206", 2009.
[NDNTLV] NDN Project Team, , "NDN Packet Format Specification.",
2016, <http://named-data.net/doc/ndn-tlv/>.
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[SNAMP] Afanasyev, A. and et al, "SNAMP: Secure namespace mapping
to scale NDN forwarding, IEEE Conference on Computer
Communications Workshops (INFOCOM WKSHPS)", 2015.
Appendix A. Ping Client Application (Consumer) Operation
This section is an informative appendix regarding the proposed ping
client operation.
The ping client application is responsible for generating echo
requests for prefixes provided by users.
When generating a series of echo requests for a specific name, the
first echo request will typically not include a PathSteering TLV,
since no TLV value is known. After an echo reply containing a
PathSteering TLV is received, each subsequent echo request can
include the received path steering value in the PathSteering header
TLV to drive the requests towards a common path as part of checking
the network performance. To discover more paths, a client can omit
the path steering TLV in future requests. Moreover, for each new
ping echo request, the client has to generate a new nonce and record
the time that the request was expressed. It will also set the
lifetime of an echo request, which will have semantics similar to the
lifetime of an Interest.
Moreover, the client application might like not to receive echo
replies due to CS hits. A mechanism to achieve that in CCNx would be
to use a Content Object Hash Restriction TLV with a value of 0 in the
payload of an echo request message. In NDN, the exclude filter
selector can be used.
When it receives an echo reply, the client would typically match the
reply to a sent request and compute the round-trip time of the
request. It should parse the PathSteering value and decode the
reply's payload to parse the the sender's name and signature. The
client should verify that both the received message and the
forwarder's name have been signed by the key of the forwarder, whose
name is included in the payload of the reply (by fetching this
forwarder's public key and verifying the contained signature). The
client can also decode the Echo Reply Code TLV to understand the
condition that triggered the generation of the reply.
In the case that an echo reply is not received for a request within a
certain time interval (lifetime of the request), the client should
time-out and send a new request with a new nonce value up to some
maximum number of requests to be sent specified by the user.
Mastorakis, et al. Expires August 27, 2017 [Page 16]
Internet-Draft ICN Ping February 2017
Authors' Addresses
Spyridon Mastorakis
UCLA
Los Angeles, CA
US
Email: mastorakis@cs.ucla.edu
Jim Gibson
Cisco Systems
Cambridge, MA
US
Email: gibson@cisco.com
Ilya Moiseenko
Cisco Systems
Cambridge, MA
US
Email: iliamo@mailbox.org
Ralph Droms
Cambridge, MA
US
Email: rdroms.ietf@gmail.com
Dave Oran
Cambridge, MA
US
Email: daveoran@orandom.net
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