Internet DRAFT - draft-ge-e164e214-bgp
draft-ge-e164e214-bgp
routing S. Ge
Internet-Draft China Mobile
Intended status: Informational AUGUST 2012
Expires: February 2, 2013
E.164/214 number BGP routing annoucement
draft-ge-e164e214-bgp-00.txt
Abstract
Recently, transferring the signaling of mobile network over IP
attracts lots of attention from people. Telephone number based on
E.164 or E.214 or SP is the traditional routing address for mobile
network, but actually, E.164, E.214 and SP is not supported by MP-BGP
protocol.
This document presents a new way to support for routing the phone
number based on E.164, E.214 or SP though MP-BGP, by extending the
MP-BGP for the Phone Number Routing. It can bring optimizing for the
network architecture and improving efficiency.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 2, 2013.
Copyright Notice
Copyright (c) 2012 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology and Abbreviation . . . . . . . . . . . . . . . . . 5
2.1. Conventions Used in This Document . . . . . . . . . . . . 5
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
3. The new method to route phone number . . . . . . . . . . . . . 5
4. Use cases and Requirements . . . . . . . . . . . . . . . . . . 7
4.1. Use case1: United Location Server (ULS) . . . . . . . . . 7
4.2. Use case2: Global data centers based on MP-BGP(BICC) . . . 8
4.3. Use case3: Global data centers based on MP-BGP(SIP) . . . 9
4.4. Use case4: ENUMDNS based on MP-BGP . . . . . . . . . . . . 9
5. BGP Extensions for Phone Number Routing Information . . . . . 10
5.1. Phone Number Routing Information NLRI . . . . . . . . . . 10
5.2. Phone Number Routing Capability Advertisement . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
9. Normative Reference . . . . . . . . . . . . . . . . . . . . . 12
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 12
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1. Introduction
Currently years, more and more service of voice is transferred over
IP network and people also pay attention to how the signaling
transfers over IP network. Signaling over IP network could probably
bring more benefits, such as higher efficiency of bandwidth, lower
cost, easy deploying and maintaining.
Traditionally, the mobile network is linked directly though switch,
addressing by telephone number and configuring manual route tables
statically. It may control the network much easier, however there
could be much more work to update configuration of the routing tables
when the network grows bigger and bigger. The IP network is linked
directly by routers, IP addressing and automatically updating the
routing tables itself. So there may need less manual work to update
the routing tables.
After combination of IP network and mobile network, phone number
addressing is still used in mobile network. Switches are
communicating among each other though routers,using IP addresses and
not connecting to other switch directly any more.
According to figure 1 below, we can find some problems:
1) Redundant procedure. Switch B receives the IP packet and sends
the IP packet to router B, during this time the packet experiences
encapsulation, acquiring the phone number though analyzing BICC and
many other protocols, checking the routing tables and at last
capsulation. Switch D repeats the same procedure. It is unnecessary
for switch B and D to process the packets.
2) There exists a shortest path between router A and router E, but
the shortest path cannot be guaranteed when the switch involved.
3) It will acquire much more manual work to update the configuration
of switch B and D when the network grows bigger and bigger.
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+--------+----+ +--------+----+ +--------+----+
| NS | ER | | NS | ER | | NS | ER |
+--------+----+ +--------+----+ +--------+----+
|1390123 | B | |1390123 | D | |1390123 | E |
+--------+----+ +--------+----+ +--------+----+
| ... | .. | | ... | .. | | ... | .. |
+--------+----+ +--------+----+ +--------+----+
calling... receiver..
+---+ +--- +---+ +---+
---->+ A'| | B' | D'| | E'+--->
+-+-+ +-+- +---+ +-+-+ +-+-+
/ / | C'| \ \
/ / +-+-+ \ \
+--++ +--++ | ++--+ ++--+
| A +-------+ B +--------+----------+ D +----+ E |
+---+ +---+ | +---+ +---+
+--------+----+ . | .-'
|IP addr | NH | `-. +-+-+ .-' +--------+----+
+--------+----+ `-. C .-' |IP addr | NH |
|10.0.0.0| B | +---+ +--------+----+
+--------+----+ +--------+----+ |10.0.0.0| E |
|switchB'| B' | |IP addr | NH | +--------+----+
+--------+----+ +--------+----+ |switchE'| E' |
|10.0.0.0| D | +--------+----+
+--------+----+
|switchD'| D' |
+--------+----+
Figure 1: the routing procedure of mobile network combined with IP
network
NS: Number Segment
ER: Egress Router
NH: Next Hop
IP addr: IP address
A/B/C/D: Router A/B/C/D
A'/B'/C'/D': switcher A'/B'/C'/D'
BGP (Border Gateway Protocol) was defined in RFC4271, which manages
the routing information based on IPv4 protocol and has not support
for IPv6, IPX, L3VPN and other network layer protocols well when
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crossing different ASs (Autonomous System). MP-BGP (multiprotocol
Extensions for BGP-4) was defined in RFC4760, which supports many
network layer protocols such as IPv6, IPX, etc. However, it is not
supported to route E.164, E.214 and SP number information by MP-BGP.
There are two attributes defined in MP-BGP protocol, which are
MP_REACH_NLRI and MP_UNREACH_NLRI, both of them contain Address
Family Identifier (AFI) used for identifying the network layer
protocol and Subsequent Address Family Identifier (SAFI) carried the
supplement to AFI.
1) MP_REACH_NLRI (Multiprotocol Reachable NLRI) is used to carry the
reachable destinations information and the next hop information used
for forwarding to these destinations.
2) MP_UNREACH_NLRI (Multiprotocol Unreachable NLRI) is used to carry
the set of unreachable destinations.
2. Terminology and Abbreviation
2.1. Conventions Used in This Document
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].
2.2. Terminology
SP numbers
These numbers comes in the range of company's ASN (Autonomous Systerm
Number) which is provided by Authority.
3. The new method to route phone number
Comparing to the method shown in Figure 1, there is new method to
route phone number though MP-BGP. The procedure is shown in Figure
2.
1) According to the figure below, switch B, C and D are not involved
in the signaling procedure, so that it can save bandwidth and
simplifying the network architecture.
2) The egress address matched with 1390123 in switch A is substituted
for the IP address of switch E.
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3) Considering the changes of mapping relationship between phone
number and IP address, the phone number routing table is
automatically learning itself just like IP routing tables.
4) It is required for the MP-BGP protocol to support large number of
phone number routing information and should not impact the IP
addresses. Additionally, the MP-BGP is mature and widespread use.
5) By configuring the parameters of NLRI, the E.164, E.214 and SP
routing information can be supported to transfer though MP-BGP.
+--------+----+
| NS | ER |
+--------+----+ +----------------------+
|1390123 | B |_________| change to the IP |
+--------+----+ |address of switch E' |
| ... | .. | +----------------------+
+--------+----+
calling... receiver..
+---+ +---+
-----+ A'| | E'+------
+-+-+ +-+-+
/ \
/ \
+--++ +---+ +---+ ++--+
| A +-------+ B +--------+-------+ D +----+ E |
+---+ +---+. | +---+ +---+
+--------+----+ `. | .-'
|IP addr | NH | ; +-+-+ .-' +--------+----+
+--------+----+ `-. C .-' |IP addr | NH |
|10.0.0.0| B | +---+ +--------+----+
+--------+----+ +--------+----+ |10.0.0.0| E |
|switchB'| B' | |IP addr | NH | +--------+----+
+--------+----+ +--------+----+ |switchE'| E' |
|10.0.0.0| D | +--------+----+
+--------+----+
|switchD'| D' |
+--------+----+
Figure 2: the new routing procedure without switcher B, C and D
involved
NS: Number Segment
ER: Egress Router
NH: Next Hop
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IP addr: IP address
A/B/C/D: Router A/B/C/D
A'/B'/C'/D': switcher A'/B'/C'/D'
4. Use cases and Requirements
4.1. Use case1: United Location Server (ULS)
The new solution based on United Location Server (ULS) integrates the
distributed devices CMN, IPSTP and ENUMDNS into one device and then,
chooses one ULS for global data center, other ULSs learn themselves
automatically. It is required to update the CMN to support IPSTP,
ENUMDNA and MP-BGP so that ULSs and MP-BGP can communicate with each
other.
Province A Province B
+---------------+ +---------------+
| +---+ | | +---+ |
|+-----+ |MSS+--+--+------+ +------+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ ULS +--+ ULS +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+--+--++ +--+---+--+--+HRL| +-----+|
| +---+ | | \ / | | +---+ |
+---------------+ | \/ | +---------------+
+---------------+ | /\ | +---------------+
| +---+ | | / \ | | +---+ |
|+-----+ |MSS+--+--+--+--++ +--+---+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ ULS +--+ ULS +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+------+ +------+--+--+HRL| +-----+|
| +---+ | | +---+ |
+---------------+ +---------------+
Province C Internetional Center
Figure 3: Global data centers based on ULS scenario
Requirements:
1) CMN changes into URL by updating. ULS is required to support CMN,
IPSTP, ENUMDNS and MP-BGP though Updating the CMN.
2) MSS can access into URLs though CMN, and HLR accesses into URLs
though IPSTP and data traffic accesses into URLs though ENUMDNS.
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3) The URLs can transfer the routing information based on phone
number among each other though MP-BGP.
4) Routing information of different traffic based on phone number is
stored in the routing table of different VPNs.
4.2. Use case2: Global data centers based on MP-BGP(BICC)
In this scenario, Reflect Routers are involved in the network. One
Reflect Router is used to server as global data center and others
update automatically themselves. It is not suitable to build big
network, but suitable for small network, due to the full connections
among the province data centers.
Province A Province B
+---------------+ +---------------+
| +---+ | | +---+ |
|+-----+ |MSS+--+--+------+ +------+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ RR +--+ RR +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+--+--++ +--+---+--+--+HRL| +-----+|
| +---+ | | \ / | | +---+ |
+---------------+ | \/ | +---------------+
+---------------+ | /\ | +---------------+
| +---+ | | / \ | | +---+ |
|+-----+ |MSS+--+--+--+--++ +--+---+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ RR +--+ RR +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+------+ +------+--+--+HRL| +-----+|
| +---+ | | +---+ |
+---------------+ +---------------+
Province C Internetional Center
Figure 4: Global data centers based on BICC scenario
Requirements:
1) The data centers, HLR and digital network entities should support
for MP-BGP.
2) The data centers and HLR should have the capacity to communicate
with MP-BGP.
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4.3. Use case3: Global data centers based on MP-BGP(SIP)
In this scenario, several Reflect Routers are involved into the
network. One Reflect Router is used for global data center, and
others update automatically themselves. The location of the data
centers is more wildly dispersed and it can be awareness of problems
that happens to data centers for network. It is unnecessary to
establish full connections among the data centers, because of the
retransmit mechanism in SIP protocol.
Province A Province B
+---------------+ +---------------+
| +---+ | | +---+ |
|+-----+ |MSS+--+--+------+ +------+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ RR +--+ RR +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+--+--++ +--+---+--+--+HRL| +-----+|
| +---+ | | \ / | | +---+ |
+---------------+ | \/ | +---------------+
+---------------+ | /\ | +---------------+
| +---+ | | / \ | | +---+ |
|+-----+ |MSS+--+--+--+--++ +--+---+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ RR +--+ RR +--+--------+MISC ||
||/WAP | +---+ | | | | | | +---+ |/WAP ||
|+-----+ |HRL+--+--+------+ +------+--+--+HRL| +-----+|
| +---+ | | +---+ |
+---------------+ +---------------+
Province C Internetional Center
Figure 5: Global data centers based on SIP scenario
Requirements:
1) All the data centers and HRL are needed to support for MP-BGP.
2) All the data centers and HRL should have the capacity to
communicate with MP-BGP.
4.4. Use case4: ENUMDNS based on MP-BGP
In this scenario, the new solution is probably the same as standard
IMS solution and is suitable for the network built by ENUMDNS. There
are many ENUMDNS used for global data center, however, it only need
one ENUMDNS to be the global data center and others update
automatically themselves.
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Province A Province B
+---------------+ +---------------+
| +---+ | | +---+ |
|+-----+ |MSS+--+--+------+ +------+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ ENUM +--+ ENUM +--+--------+MISC ||
||/WAP | +---+ | | NDS | | DNS | | +---+ |/WAP ||
|+-----+ |HRL+--+--+--+--++ +--+---+--+--+HRL| +-----+|
| +---+ | | \ / | | +---+ |
+---------------+ | \/ | +---------------+
+---------------+ | /\ | +---------------+
| +---+ | | / \ | | +---+ |
|+-----+ |MSS+--+--+--+--++ +--+---+--+--+MSS| +-----+|
|| | +---+ | | | | | | +---+ | ||
||MISC +--------+--+ ENUM +--+ ENUM +--+--------+MISC ||
||/WAP | +---+ | | DNS | | DNS | | +---+ |/WAP ||
|+-----+ |HRL+--+--+------+ +------+--+--+HRL| +-----+|
| +---+ | | +---+ |
+---------------+ +---------------+
Province C Internetional Center
Figure 6: Global data centers based on ENUMDNS scenario
Requirements:
1) ENUMDNS should support for MP-BGP.
2) ENUMDNS should have the capability of communicate with MP-BGP.
5. BGP Extensions for Phone Number Routing Information
5.1. Phone Number Routing Information NLRI
Phone Number Routing Information is exchanged in BGP UPDATE messages
using the MP_REACH_NLRI and MP_UNREACH_NLRI attributes defined for
MP-BGP [RFC 4760]. The AFI value 8 is used, and a new SAFI value
needs to be assigned for phone number routing information.
"Length of Next Hop Network Address" in the MP_REACH_NLRI attribute
indicates the length of the Next Hop Address.
"Network Address of Next Hop" in the MP_REACH_NLRI attribute SHOULD
be set to the IP address of the originating speaker of the Phone
Number Routing Information. It is an IPv4 address if the length of
Next Hop address is 4 octets, or an IPv6 address if the length of the
Next Hop address is 16 octets.
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The NLRI field in the MP_REACH_NLRI and MP_UNREACH_NLRI is encoded as
one or more 2-tuples of the form ( length, prefix ). The length
field indicates the length (in bits) of the prefix. The structure of
the Prefix field is as table 3 below:
+-----------------------------------+
| Type (1 octet) |
+-----------------------------------+
| RD (8 octets) |
+-----------------------------------+
| Phone number prefix (variable) |
+-----------------------------------+
Table 1: Phone number prefix field
Type: indicates the type of the phone number prefix:
1: E.164 number prefix
2: E.214 number prefix
3: SP number prefix
RD: Route Distinguisher, encoded as described in [RFC 4364].
Phone number prefix: a variable length prefix of the phone number.
The prefix is encoded in Binary-Coded Decimal (BCD) to represent a
decimal phone number prefix.
5.2. Phone Number Routing Capability Advertisement
In order for two BGP speakers to exchange the Phone Number Routing
Information, they must use a BGP Capabilities Advertisement to ensure
that they both are capable of properly processing such an NLRI. This
is achieved as specified in [RFC4760], by using capability code 1
(multiprotocol BGP) with an AFI of 8 and a SAFI of TBD.
6. IANA Considerations
This document defines a new NLRI called "Phone Number Routing
Information". A new SAFI value needs to be assigned for this new
NLRI by the IANA.
This document defines the Phone Number Routing Capability for BGP.
The Capability code needs to be assigned by the IANA.
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7. Security Considerations
This extension to [RFC 4760] does not change the underlying security
issues inherent in the existing BGP and [RFC 4760].
8. Acknowledgments
Thanks to my colleagues for their sincerely help and comments when
drafting this document.
9. Normative Reference
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3761] Faltstrom, P. and M. Mealling, "The E.164 to Uniform
Resource Identifiers (URI) Dynamic Delegation Discovery
System (DDDS) Application (ENUM)", RFC 3761, April 2004.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
January 2007.
[RFC6141] Camarillo, G., Holmberg, C., and Y. Gao, "Re-INVITE and
Target-Refresh Request Handling in the Session Initiation
Protocol (SIP)", RFC 6141, March 2011.
Author's Address
Shu Ge
China Mobile
Financial Street No.29
Xicheng District, Beijing 10033
China
Phone: +86-010-52686688-1734
Email: geshu@chinamobile.com
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